LEASE AGREEMENT BETWEEN SSI 900 MIDDLESEX MA LP, as Landlord AND QUANTERIX CORPORATION, as Tenant WITH RESPECT TO 900 MIDDLESEX TURNPIKE, BUILDING 1 BILLERICA, MASSACHUSETTS

SSI 900 MIDDLESEX MA LP, as Landlord

QUANTERIX CORPORATION, as Tenant

900 MIDDLESEX TURNPIKE, BUILDING 1

BILLERICA, MASSACHUSETTS

1.1. SUBJECTS REFERRED TO.

Each reference in subsequent Articles of this Lease Agreement (this Agreement or Lease ) to any of the following subjects shall incorporate the data stated for that subject in this Section 1.1.

The Exhibits listed below in this Section are incorporated in this Agreement by reference and are to be construed as part of this Agreement:

EXHIBIT A Legal Description of the Lot

EXHIBIT B Plan of Premises

EXHIBIT C Initial Plan of Tenant s Initial Work and Budget

EXHIBIT D ACH Electronic Fund Transfer Form

EXHIBIT E Form Letter of Credit

EXHIBIT F Building Services

EXHIBIT G Rules and Regulations

EXHIBIT H Decommissioning Requirements and Decommissioning Plan

EXHIBIT I Form of Landlord Estoppel Certificate

EXHIBIT J Form of Tenant Estoppel Certificate

EXHIBIT K Work Letter

EXHIBIT L Delivery Condition Items

EXHIBIT M Landlord s Equipment

EXHIBIT N List of Site Assessments

EXHIBIT O Existing Mortgagee s Form of SNDA

EXHIBIT P Tenant s Exterior Signage

EXHIBIT Q Form of Commencement Date Agreement

1.3. SECURITY DEPOSIT.

$1,000,000.00 irrevocable standby Letter of Credit (as defined in Section 4.3 hereof) obtained and delivered in accordance with the terms and conditions of Section 4.3 hereof; provided, however, so long as Tenant is not then in default, and that prior to any Reduction Date (as set forth in the table below) there has occurred no monetary Event of Default, then, as of each Reduction Date, Landlord shall permit the amount of the letter of credit to be reduced to (or a replacement letter of credit may be issued in the amount of) the corresponding New Letter of Credit Amount (as set forth below) as follows:

To obtain the reduction, (a) Tenant shall coordinate for the amendment or replacement of the original Letter of Credit that Landlord shall hold to reduce the Letter of Credit as noted above, and (b) Tenant shall pay all costs and expenses associated with such amendments to or replacements of, the Letter of Credit, which Letter of Credit shall always remain in the form and subject to the provisions of Section 4.3 of this Agreement.

Subject to and with the benefit of the provisions of this Agreement, Landlord hereby leases to Tenant and Tenant leases from Landlord, for the Term, the Premises, but excluding the Building s exterior walls and exterior windows (except the inner surfaces thereof), roof and roof membrane, floor slabs, load bearing elements, footings, foundations, columns and other structural elements. Landlord makes no representation or warranty as to the suitability of the Premises for Tenant s intended use. Tenant shall, at its own cost and expense, obtain and maintain any and all licenses, permits, and approvals necessary or appropriate for its use, occupation and operation of the Premises for the Permitted Uses. Tenant s inability to obtain or maintain any such license, permit or approval necessary or appropriate for its use, occupation or operation of the Premises shall not relieve it of its obligations under this Lease, including the obligation to pay Base Rent and Additional Rent.

2.2. RIGHT TO EXTEND.

Subject to the following, Tenant shall have the right (the Extension Option ) to extend the Lease Term for two (2) successive periods of five (5) years each (each, an Term Extension and collectively the Term Extensions ), by giving Landlord written notice (the Renewal Notice ) irrevocably exercising such extension, which notice must be received by Landlord not later than the date twelve (12) months prior to the otherwise applicable last day of the Lease Term (as the same may have been extended for the first Term Extension), time being of the essence. If each such extension is timely and properly exercised, the Lease Term shall be automatically extended to include the applicable Term Extension upon the same terms and conditions except that (i) during the second Term Extension, Tenant shall have no further option to extend the Term, (ii) the Base Rent for each Term Extension shall be the greater of (a) ninety-five (95%) of the Fair Market Rental Value for the Premises as determined in accordance with the terms hereof, and (b) the Base Rent then in effect immediately prior to the extension of the then current Term of this Agreement, and (iii) Landlord shall have no obligation to prepare,

refurbish or construct the Premises or any part thereof prior to the commencement of the Extension Term or otherwise provide any amount of free rent or improvement allowance in respect of the Premises. Any exercise of an Extension Option by Tenant as provided herein shall be irrevocable. If for any reason the Fair Market Rental Value has not been determined as of the commencement date of the Term Extension, Tenant initially shall pay Base Rent in an amount equal to one hundred three percent (103%) of the Base Rent in effect immediately prior to the commencement date of the Term Extension , with a retroactive adjustment to be made within fourteen (14) days after the determination of Fair Market Rental Value. If Tenant exercises the Extension Option, within fifteen (15) days after the determination of the Fair Market Rental Value for the Premises as herein provided, the Landlord and Tenant shall execute an amendment to this Lease confirming same, provided that the failure of either party to do so shall not affect the rights and obligations of the parties hereunder. Tenant shall not be entitled to exercise its extension right pursuant to the terms of this Section if, at the time of exercise or at the commencement of the Term Extension, (i) Tenant is in default beyond any applicable notice and cure period provided in this Lease, or (ii) this Lease is not in full force and effect.

In the event Tenant timely delivers its Renewal Notice as set forth above, Landlord shall notify Tenant of the applicable Fair Market Rental Value as determined by Landlord within thirty (30) days after receipt of Tenant s Renewal Notice. Tenant shall, within fifteen (15) days after receipt of Landlord s determination of the Fair Market Rental Value, notify Landlord in writing whether Tenant accepts or rejects Landlord s determination of the Fair Market Rental Value. If Tenant fails to notify Landlord that it rejects Landlord s determination of the Fair Market Rental Value within such fifteen (15) day period (time being of the essence), Tenant shall be deemed to have irrevocably accepted Landlord s determination of the Fair Market Rental Value. If Tenant rejects Landlord s determination of the Fair Market Rental Value within such fifteen (15) day period (time being of the essence), then Landlord and Tenant shall each select a Qualified Broker (as defined below) within ten (10) business days following delivery of Tenant s rejection notice. If a party fails to timely select a Qualified Broker, the determination of the Fair Market Rental Value for the Premises shall be made by the Qualified Broker selected by the other party. If each party selects a Qualified Broker, the two (2) Qualified Brokers selected by Landlord and Tenant shall select a third Qualified Broker by mutual agreement reached within five (5) business days after selection of the first two (2) Qualified Brokers by Landlord and Tenant. Within ten (10) business days after the third Qualified Broker has been selected, all of the Qualified Brokers shall meet to attempt to agree upon the Fair Market Rental Value for the Premises. If the Qualified Brokers are unable to reach agreement, all Qualified Brokers shall, within ten (10) business days after the expiration of the preceding ten (10) business day period, arrange to simultaneously submit to Landlord and Tenant in writing their determinations of Fair Market Rental Value. Landlord shall be responsible for any and all costs associated with the retention of the Qualified Broker selected by Landlord, Tenant shall be responsible for any and all costs associated with the retention of the Qualified Broker selected by Tenant and Landlord and Tenant shall each be responsible for one half (1/2) of any and all costs associated with the retention of the third Qualified Broker. All brokers selected pursuant to this section shall be (a) a commercial real estate broker licensed in Massachusetts, specializing in the leasing of laboratory space in the Bedford, Billerica and Burlington, Massachusetts submarket, with not less than ten (10) years experience in appraising comparable commercial properties in such market and recognized as reputable within the local real estate industry, and (b) independent and none of the brokers nor their firms shall have been employed by Landlord (with respect to the Building),

Tenant or their affiliates for the immediately preceding five (5) years (each such broker being defined herein for purposes of this paragraph as a Qualified Broker ). The Fair Market Rental Value shall be the average ( average shall refer herein to the sum of the fair market rent determinations divided by the number of brokers) of the fair market rent determinations of the three (3) brokers, unless the highest determination of the three (3) brokers is greater than 10% higher than the next highest determination, in which case it shall be discarded, or unless the lowest of the three (3) determinations is greater than 10% lower than the next lowest determination, in which case it shall be discarded. If one determination is discarded, then the Fair Market Rental Value shall be the average of the remaining two (2) determinations. If both the highest determination and the lowest determination are discarded, then the Fair Market Rental Value shall be the remaining determination. The Fair Market Rental Value for the Premises determined in accordance with the terms hereof shall be final and binding on Landlord and Tenant.

Tenant shall be permitted entry into the Premises beginning on the date of execution of this Lease solely for the limited purpose of performing Tenant s Initial Work subject to and in accordance with the terms and conditions of the Work Letter attached hereto as Exhibit K and incorporated herein (the Work Letter ), but any such entry or entries shall be at the Tenant s sole risk. Tenant s access of the Premises prior to the Term Commencement Date ( Tenant s Early Access ) for purposes of performing the Tenant s Initial Work as provided above shall be subject to all of the terms and conditions of this Lease, except that Tenant shall not be required to pay Base Rent or Additional Rent during such period, other than charges for electricity and other utilities which shall be payable by Tenant.

2.4. COMMENCEMENT DATE AGREEMENT.

Following the Term Commencement Date, Landlord may prepare and submit to the Tenant a Commencement Date Agreement in the form of EXHIBIT Q, completed in good faith by Landlord, and executed by Landlord. The information inserted on the Commencement Date Agreement shall be controlling and conclusive and shall prevail over any inconsistent provision in this Lease on (a) the mutual execution of the Commencement Date Agreement by Landlord and Tenant or (b) the lapse of fifteen (15) days following delivery of the Commencement Date Agreement to Tenant without Tenant delivering to Landlord a written objection to all or part of the information in the Commencement Date Agreement. If Tenant does object in good faith to any information set forth in the Commencement Date Agreement, it shall execute the Commencement Date Agreement subject to its specifically-stated, written objections. Tenant must explain the reasons for its objections in reasonable detail. That portion of the Commencement Date Agreement to which no objection was made shall be conclusive and controlling. Pending resolution of any dispute by agreement or a final determination by a court of competent jurisdiction in accordance with this Lease, Landlord s information as inserted in the Commencement Date Agreement shall be utilized subject to any later adjustment agreed or found to be appropriate. Tenant s refusal or failure to execute a Commencement Date Agreement shall neither prevent nor delay the occurrence of the Term Commencement Date. In no event shall the Commencement Date Agreement be recorded.

STATUS OF PREMISES; ALTERATIONS; MAINTENANCE

Tenant shall accept the Premises in its as is and where is condition as of the Term Commencement Date, provided that (a) the items set forth on Exhibit L - Part I shall be satisfied as of the Term Commencement Date, and (b) Landlord shall have removed the equipment designated for removal as set forth on Exhibit M ( Landlord s Equipment ), which equipment shall be retained by Landlord as Landlord s property (collectively, the Delivery Condition ). Landlord shall substantially complete each of the items set forth on Exhibit L - Part II within a commercially reasonable period after the Term Commencement Date. Tenant may not make any alterations or changes to the Premises, or remove any of Landlord s property that is affixed to the Premises, without Landlord s prior written consent, which consent may be withheld or conditioned in Landlord s sole discretion. Without limiting the generality of the foregoing, Tenant shall not (i) modify nor penetrate nor make any structural change nor addition to the Building, including without limitation, the Premises, nor the roof, Building envelope, load bearing walls, foundation nor any Building systems (collectively, Building Structure/Systems ), or (ii) remove or alter any of the Premises infrastructure, fixtures, built-ins, and/or equipment that is affixed to the Premises as of the date hereof in any respect, without, in either case, first obtaining, on each occasion, Landlord s consent in writing, which Landlord may grant or withhold in Landlord s sole discretion, and, if Landlord so consents, then only at Tenant s expense using only a contractor on Landlord s list of approved contractors for the Building Structure/Systems, and in a lawful manner and upon such terms and conditions as Landlord, by such writing, shall approve, which shall include, without implied limitation, maintenance of insurance in form and substance satisfactory to Landlord. Any Landlord approval of such alterations may be conditioned upon the Tenant s delivery to Landlord of such documents as Landlord may reasonably require to understand or assess the scope of the proposed changes, and/or additional protections required as arise therefrom, including, without limitation, certificates of insurance, timeline, list of required permits or approvals, and stamped architectural drawings or other plans together with cost affidavits and evidence of available funds. Landlord shall deliver notice of its consent or withholding of consent in connection with any such plans proposed by Tenant requiring Landlord consent and in connection with any selection of contractors proposed by Tenant requiring Landlord consent within ten (10) business days after Landlord receives the same from Tenant (which notice of Landlord shall, in the case of a withholding of consent, contain a description of the reasons for Landlord s withholding of consent). If Landlord fails to approve or disapprove of Tenant s proposed plans or contractors within such ten (10) business day period, Tenant may give Landlord notice of such failure and if such notice includes a statement at the top of the page having a heading in at least 12-point type, bold and all capital letters stating LANDLORD S FAILURE TO RESPOND TO TENANT S REQUEST FOR APPROVAL OF THE ENCLOSED PLANS OR CONTRACTORS WILL RESULT IN LANDLORD S DEEMED APPROVAL OF SUCH PLANS OR CONTRACTORS , then Landlord shall be deemed to have approved such plans and/or contractors (as applicable) if Landlord fails to respond to such request within an additional five (5) business days. Notwithstanding anything in this Section 3.1 to the contrary, Tenant shall provide Landlord at least fourteen (14) days prior notice thereof, but shall not be

required to obtain Landlord s consent to perform interior, non-structural alterations that: (a) cost less than One Hundred Thousand Dollars ($100,000.00) in the aggregate (including all related alterations which may be part of a larger project or a series of related projects), not including the cost of furniture, trade fixtures and equipment, and (b) do not affect the Building Structure/Systems (alterations satisfying the foregoing clauses (a) and (b) are referred to herein as Permitted Alterations . With the exception of the requirement to obtain Landlord s consent, the performance or construction of any Permitted Alterations shall comply with all other terms and conditions of this Lease applicable to any alterations or other work by Tenant at the Premises. Tenant shall provide Landlord with copies of any construction plans and as-built plans that Tenant obtains for any Permitted Alterations.

To the extent that Landlord approves any alterations or other work by Tenant at the Premises, the approval is limited to Tenant s work as shown on the plans and specifications approved by Landlord, and Tenant s work, including, without limitation, matters related to or arising out of the design and/or construction of the work, including, without limitation, any errors or omissions contained therein, and/or the necessity of other work required by such work to comply with legal requirements or directives, shall be Tenant s responsibility without cost or liability to Landlord. All work performed by or for Tenant under this Lease is performed for the sole benefit of Tenant and at Tenant s sole cost and expense and shall be done in a good and workmanlike manner, in compliance with all applicable laws and using new and high quality materials. Tenant agrees that, with respect to all work of any nature performed by or for Tenant, including, without limitation, Tenant s work, whether related to leasehold improvements, alterations or any other type of manner of work, Tenant and Tenant s agents, contractors, workers, mechanics, suppliers and invitees shall work in harmony with Landlord and such other contractors, workers, mechanics, suppliers and invitees as shall be working there from time to time, if any. Upon completion of any work by Tenant, Tenant shall provide Landlord with As-Built electronically recorded drawings on a disk in AutoCADD format. Any alteration or addition shall be consistent in appearance with the rest of the Building and Landlord s Property and shall be made only after duly obtaining all required permits and licenses from all governmental authorities. Tenant will deliver to Landlord in writing a schedule setting forth the details and location of all such alterations or additions and, upon request, provide Landlord lien waivers from time to time from all parties performing work related to the Premises or services for Tenant. This Lease addresses the respective obligations of Landlord and Tenant for maintenance, repairs and replacements, and, to the fullest extent permitted by law, Tenant waives the provisions of G.L. c. 186 19.

3.3. TENANT S INITIAL WORK; IMPROVEMENT ALLOWANCE.

3.3.1. TENANT S INITIAL WORK. Subject to the provisions of the Work Letter, Landlord understands that Tenant may wish to make certain alterations and improvements to the Premises at the start of the Term so as to originally configure the Premises for Tenant s intended uses (such work the Tenant s Initial Work ). Tenant has provided Landlord with conceptual plans and a general budget for Tenant s Initial Work, copies of which are attached hereto as Exhibit C. Tenant acknowledges and agrees that Landlord has not approved Tenant s Initial Work, and that any such approval will be provided in a separate writing signed by Landlord.

Landlord hereby consents to and approves Tenant s use and engagement of both GRLA Architects and JM Coull Construction (the Approved Professionals ) to design and undertake to construct Tenant s Initial Work. Landlord shall have the right to have its representative at the Premises at all times during the construction of the Tenant s Initial Work to review and monitor the performance of same, and Tenant shall pay Landlord, within ten (10) days after Landlord s written demand, a construction monitoring fee equal to one percent (1%) of the total hard costs of Tenant s Initial Work. Landlord reserves the right to deduct such fee from the Improvement Allowance (as defined below).

Prior to commencing any work on the Tenant s Initial Work, Tenant shall submit a budget for the Tenant s Initial Work, including all hard and soft costs such as and without limitation, all labor and materials, architectural, engineering, permitting, project management, and space planning fees ( Itemized Costs ) to Landlord for Landlord s approval. Upon Landlord s approval of such a budget, the same shall be referred to herein as the Approved Budget .

3.3.2. IMPROVEMENT ALLOWANCE. Subject to the terms hereof, Landlord shall grant an allowance to Tenant in an amount not to exceed the aggregate of (a) Six Million Eight Hundred Seventy Thousand Dollars ($6,870,000.00) (the Basic Improvement Allowance ) to be used solely to reimburse the Tenant for the Itemized Costs, and (b) One Million Three Hundred Thousand Dollars ($1,300,000.00) (the HVAC Allowance and together with the Basic Improvement Allowance, the Improvement Allowance ) to be used solely to reimburse the Tenant for that portion of the Itemized Costs of replacing the HVAC units serving the Premises and related control systems . The Improvement Allowance shall be available for disbursement subject to and in accordance with the terms and conditions hereof (including the Work Letter), provided that at no time shall Landlord be required to make a disbursement of any of the Improvement Allowance if following such advance the aggregate amount of the Improvement Allowance advanced by Landlord would exceed Landlord s Share of the aggregate amount of the Itemized Costs incurred by Tenant through such date. As used herein, Landlord s Share means and refers to a fraction (expressed as a percentage), the numerator of which is the original amount of the Improvement Allowance and the denominator of which is the total amount of the Approved Budget (taking into account any increases in the Approved Budget, including increases as a result of change orders requested by Tenant and approved by Landlord in accordance with the terms of the Work Letter). Conditioned upon and provided that the Conditions Precedent (as defined below) are satisfied for each reimbursement request, and satisfied for each request no later than the date which is two (2) years after the Term Commencement Date (the Required Completion Date ), Landlord shall pay to Tenant within thirty (30) days of satisfaction of the Conditions Precedent Landlord s Share of the Itemized Costs The Conditions Precedent are: (a) Tenant is not in default under this Lease beyond any applicable notice and cure period provided in this Lease, and Tenant is in full compliance with all requirements under this Section 3.3 concerning Tenant s Initial Work, (b) Tenant has complied with all of the terms and conditions of the Work Letter that are conditions precedent that required to be satisfied prior to the disbursement of any portion of the Improvement Allowance, and (c) Tenant has provided Landlord an itemized accounting of Tenant s costs for such Tenant s Initial Work for which it seeks reimbursement ( Itemized Costs ), of which not more than twenty-five (25%) percent shall be laboratory case work and soft costs, as more particularly set forth in the Work Letter.

Notwithstanding anything herein to the contrary, in the event that Tenant has not completed the Tenant s Initial Work and satisfied all of the conditions for payment of the Improvement Allowance on or before the Required Completion Date, any remaining unfunded portion of the Improvement Allowance shall be deemed forfeited and Landlord shall have no further obligation to make any advances of the Improvement Allowance, provided, however, that so long as no Event of Default has occurred and is continuing, an amount equal to the Maximum Unused Allowance Amount (as defined below) shall inure to Tenant s benefit and shall be applied against Base Rent payable beginning as of the first day of the first calendar month following the Required Completion Date, and continuing for such number of calendar months as is necessary for said Maximum Unused Allowance Amount to be fully applied to Base Rent that subsequently comes due and payable hereunder. For purposes of this Agreement, the Maximum Unused Allowance Amount shall mean an amount equal to the lesser of (i) the aggregate amount of any portion of the Basic Improvement Allowance that was not Advanced (as defined in the Work Letter) or otherwise disbursed by Landlord, for any reason or no reason whatsoever, as of the date immediately following the Required Completion Date, or (ii) an amount equal to One Million Seven Hundred Twenty-Five Thousand Dollars ($1,725,000.00). For the avoidance of doubt, the Maximum Unused Allowance Amount shall not be applied to abate or reduce Tenant s obligations with respect to Additional Rent, and no unused portion of the HVAC Allowance may be used to abate or reduce any of Tenant s obligations with respect to Base Rent or Additional Rent. Except as set forth above, Tenant shall not otherwise be entitled to any credit, offset or abatement with respect the unused Improvement Allowance funds.

Tenant shall not overload, damage or deface the Premises nor shall it suffer or permit the same to be done, nor shall it commit any waste. Tenant shall initiate and carry out a program of regular maintenance and repair of the Premises so as to impede, to the extent reasonably practicable, deterioration by ordinary wear and tear. Without limiting the foregoing, Tenant shall not connect to any utility or Building system anything which would exceed the capacity of any related distribution system, equipment or conductor serving the Premises.

3.5. MAINTENANCE; REPAIRS; AND YIELD-UP.

Tenant agrees that from Tenant s entry to the Premises until the end of the Term hereof and during any holdover, it will keep the Premises neat and clean and maintain the same in good repair and condition (other than Landlord s obligations under Sections 7.1 and 7.2 of this Lease) and in a design, decor and character consistent with the rest of Landlord s Property; the Tenant s obligation to so clean, maintain and repair the Premises shall apply to all of the Premises, including, without limitation, all doors, glass, fixtures, interior walls, drains, floors, carpeting, Tenant Responsibilities and any other systems exclusively serving the Premises. Tenant is also responsible to replace any of the foregoing items or other portions of the Premises that are destroyed or deteriorate from Tenant s failure to take customary measures to prevent their destruction or deterioration. In addition, Tenant is responsible, at Tenant s sole cost and expense, for (i) the cleaning of the Premises and ordinary trash removal from the Premises to the dumpster, and (ii) the proper use, management, storage, removal and off-site disposal of any and all Hazardous Materials in accordance with Environmental Requirements. Tenant, and not Landlord, is responsible at Tenant s sole cost and expense to maintain, repair and replace above

ground storage tanks ( ASTs ) and secondary containment associated with the ASTs installed by Tenant in accordance with Section 6.1.15(b), lab hoods, lab areas, wastewater systems and anything Tenant or another at Tenant s direction installed, modified, added and/or altered, HVAC and/or other Building systems, including, without limitation, any HVAC units, fixtures and equipment and/or related work, including, without limitation, duct work whether part of Tenant s work or other work later performed on the Premises by Tenant or any other Tenant Parties such as for a server room or lab space (collectively, Tenant Responsibilities ). Tenant shall maintain a complete, full preventative HVAC service contract with a contractor acceptable to Landlord and Tenant, a copy of which contract shall be provided to Landlord for the maintenance (at least quarterly), repair and upkeep of the HVAC related to Tenant Responsibilities, and Tenant shall be responsible, if necessary, for replacing any portion of the HVAC related to Tenant Responsibilities. In addition to and not in limitation of Tenant s other obligations hereunder (including, without limitation, Tenant s obligation to yield up the Premises) Tenant shall, during the Lease Term, maintain, repair and replace as necessary, all additions, alterations and improvements to or for the benefit of the Premises or the business at the Premises, including ASTs and secondary containment and shall maintain the same in good working order and condition. At the end of the Term or sooner termination of this Lease, Tenant shall peaceably surrender or deliver up the Premises to Landlord having, at Landlord s option removed all ASTs and secondary containment and restored (a) any so-called clean room created by or at the direction of Tenant to the condition such space was in prior to the Term Commencement Date, and (b) any other space, by either (x) having first removed, at Tenant s sole cost and expense, all or certain designated erections, alterations, additions, floor coverings and wall treatments at the Premises made to or upon the same and repairing the Premises to the same condition as existing upon execution of this Lease or (y) leaving all or such portions of such erections, alterations, additions, floor coverings and wall treatments as Landlord has not designated for removal in good condition and repair, and with the Premises broom clean, with all utilities safely capped, and in good repair and condition, and removing all signs and lettering and all personal property, goods and effects belonging to Tenant or anyone claiming through or under Tenant, including, without limitation, furniture, trade fixtures and equipment, cabling, wiring and other communications equipment. Landlord s consent shall not be unreasonably withheld for non-structural, non-Building system interior changes to the Premises.

3.6. TRADE FIXTURES AND EQUIPMENT.

Any trade fixtures installed in, or attached to, the Premises by, and at the expense of, Tenant shall remain the property of Tenant. Tenant shall have the right, at any time and from time to time during the Term of this Lease, to remove any and all of such trade fixtures, which it may have installed in, or attached to, the Premises, during the Term. In addition, at the expiration of this Lease, Tenant shall, in addition to Tenant s requirements to comply with Tenant s yield-up obligations under this Lease, remove all of Tenant s trade fixtures and equipment and restore the Premises and related areas to its original condition. At any time that Tenant removes its trade fixtures, Tenant shall promptly repair the Premises as a result of any damage to, or destruction of, the Premises caused by the removal of its trade fixtures. Notwithstanding anything to the contrary contained in this Agreement, no lab hoods, exhaust hoods, cold rooms, casework, air conditioning and heating equipment, and utility or structural improvements for which Landlord made the Improvement Allowance available shall be considered Tenant trade fixtures or other property of Tenant for purposes of this Section 3.6, all

of which shall remain the Premises and shall be the property of Landlord upon the termination of this Agreement without requirement of the payment of any compensation or consideration.

BASE RENT, ADDITIONAL RENT AND SECURITY DEPOSIT

In consideration of the lease of the Premises pursuant to this Lease, Tenant shall pay Base Rent in the applicable amount set forth in Article I payable in equal monthly installments of one-twelfth of the annual Base Rent, which shall be paid without offset or deduction for any reason (except as otherwise expressly provided in this Lease), in advance, on the first day of each calendar month during the Term hereof, subject to the following, and also on the Term Commencement Date, should it be on any day other than a first day of the month, a proportionate part of the monthly Base Rent shall be paid for such month. Notwithstanding the foregoing, Tenant shall (i) have no obligation to pay Base Rent that would otherwise be payable during the first five (5) months of the Lease Term (the Initial Free Rent Period ), and (ii) receive an abatement of fifty percent (50%) of the next successive thirteen (13) months of Base Rent that would otherwise be payable during the next successive thirteen (13) months of the Lease Term (the Partial Rent Abatement Period ). During the Initial Free Rent Period, the free rent set forth above is for Base Rent and Additional Rent for Taxes and/or Operating Costs; provided that in all events Tenant shall pay the cost of utilities supplied to the Premises during the Initial Free Rent Period and for any services directly contracted for by the Tenant. During the Partial Rent Abatement Period, the rent abatement set forth above is for Base Rent only and Tenant shall pay all Additional Rent, including but not limited to Additional Rent for Taxes and/or Operating Costs, and for the cost of utilities supplied to the Premises during the Partial Rent Abatement Period and for any services directly contracted for by the Tenant. Base Rent and Additional Rent shall be paid when due hereunder either (a) by wire transfer and/or an electronic funds transfer system ( EFT ) arranged by and among Tenant, Tenant s bank and Landlord with Tenant submitting to Landlord at the time of Tenant s execution and delivery of this Lease to Landlord a completed ACH electronic fund transfer form similar to the one attached hereto as Exhibit D and sufficient to allow Landlord to make such transfers, or (b) by check sent to Landlord s office at Landlord s Address or at such other place as Landlord shall from time to time designate in writing. If Tenant is using checks, rent checks shall be made payable to or as Landlord may designate from time to time in writing. The parties hereto acknowledge and agree that the obligations owing by Tenant under this Section are rent reserved under this Lease, for all purposes hereunder, and are rent reserved within the meaning of Section 502(b)(6) of the Bankruptcy Code or any successor provision thereto.

4.2. CERTAIN ADDITIONAL RENT.

Tenant shall pay, without offset or deduction for any reason, Additional Rent on account of Taxes, Costs of Electricity and Operating Costs, which amounts are more particularly set forth in subsections 4.2.1., 4.2.2. and/or 4.2.3., below, and all other fees, charges, expenses, fines, assessments or other sums payable by Tenant to Landlord hereunder. If Tenant fails to pay any Additional Rent and the same continues beyond any applicable notice, grace and cure period,

Landlord shall have all the rights and remedies for Tenant s failure to pay Base Rent. The parties hereto acknowledge and agree that the obligations owing by Tenant under this section are rent reserved under this Lease, for all purposes hereunder, and are rent reserved within the meaning of Section 502(b)(6) of the Bankruptcy Code or any successor provision thereto.

4.2.1. PAYMENT OF REAL ESTATE TAXES AND OTHER TAXES.

(i) Tenant shall pay to the Landlord as Additional Rent an amount equal to such Taxes as have accrued during the Term and remain unpaid. Such Tenant s Taxes shall be estimated in good faith by Landlord at the end of each Fiscal Year, and thereafter be payable to Landlord in equal estimated monthly installments on the first day of each month together with the payment of Base Rent, subject to readjustment when the actual amount of Taxes is determined. After readjustment, any shortage shall be due and payable by Tenant within 15 days of demand by Landlord and any excess shall be credited against future Additional Rent obligations, or refunded if the Term of this Lease has ended and the Tenant has no further obligations to Landlord. If the taxing authority provides an estimated tax bill, then monthly installments of Taxes shall be based thereon until the final tax bill is ascertained. Landlord shall furnish to Tenant, upon Tenant s request, a copy of the tax bill or any estimated tax bill.

(ii) Taxes shall mean all taxes, assessments, betterments, water or sewer entrance fees and charges including general, special, ordinary and extraordinary, environmental, or any other charges (including charges for the use of municipal services if billed separately from other taxes), levied, assessed or imposed at any time by any governmental authority upon or against the land, the Building, other buildings, the fixtures, signs and other improvements thereon then comprising the Property and the Lot. This definition of Taxes is based upon the present system of real estate taxation in the Commonwealth of Massachusetts, excluding income taxes on Landlord s income, franchise taxes, capital stock transfer taxes, estate taxes and inheritance taxes; provided, however, and notwithstanding the foregoing if taxes upon rentals or any other basis shall be substituted, in whole or in part, for the present ad valorem real estate taxes, the term Taxes shall be deemed changed to the extent to which there is such a substitution for the present ad valorem real estate taxes. Fiscal Year shall mean July 1st through June 30th next following, or such other tax period as may be established by law for the payment of Taxes;

(iii) If, after Tenant shall have made any payment under this subsection 4.2.1., Landlord shall receive a refund of any portion of the Taxes paid on account of any Fiscal Year in which such payments shall have been made as a result of an abatement of such Taxes, by final determination of legal proceedings, settlement or otherwise ( Proceedings ), Landlord shall, to the extent Tenant is not in default nor would be in default but for the giving of notice, the passage of time or both, within thirty (30) days after

receiving the refund, pay Tenant the refund, if any, which shall be adjusted if Tenant s original payment covered a shorter period than covered by the refund, less the expense (including, but not limited to, reasonable attorneys fees, costs and appraisers fees) allocable to Tenant s share and incurred by Landlord in connection with any such Proceeding. Landlord shall have sole control of all tax abatement proceedings.

(iv) If the Term Commencement Date of this Lease is not on July 1, or the expiration or termination of this Lease is not on June 30th, the Tenant s obligation in respect of Taxes shall be prorated. If the final tax bill for the Fiscal Year in which such expiration or termination of this Lease occurs shall not have been received by Landlord, then within thirty (30) days after the receipt of the tax bill for such Fiscal Year, Landlord shall make appropriate adjustments of either final amounts of Taxes due from Tenant or credits or refunds due to Tenant.

(v) Without limiting the generality of the foregoing, Tenant shall pay all rent and personal property taxes attributable to its signs or any other personal property including, but not limited to, its trade fixtures equipment and other personal property of Tenant in the Premises.

(vi) Anything in this Lease to the contrary notwithstanding, if (i) Landlord has not notified Tenant of Landlord s intention to file an application with applicable governmental authorities for reduction of the assessed valuation of the Premises and/or the Building (any such application being herein called a Tax Protest ), or (ii) after filing a Tax Protest, Landlord notifies Tenant that Landlord does not intend to commence an action or proceeding in a court of appropriate jurisdiction seeking judicial review of the denial of any Tax Protest (any such action or proceeding being herein called a Tax Proceeding ), then subject to the last sentence of this paragraph Tenant shall have the right to require Landlord to file such a Tax Protest or commence and diligently prosecute such a Tax Proceeding, as the case may be, provided and upon the condition that (y) Tenant exercises such right by notice to Landlord (a Tenant s Tax Protest Notice ) given at least thirty (30) days (but not more than forty-five (45) days) prior to the latest date on which such a Tax Protest validly may be filed or such a Tax Proceeding validly may be commenced, as the case may be; and (z) Tenant s notice is accompanied by a signed statement agreeing that all costs and expenses incurred by Landlord in connection with such Tax Protest or Tax Proceeding shall be paid by the Tenant within ten (10) days after demand by Landlord (Landlord agreeing, however, that such costs and expenses shall be reimbursed to Tenant from and to the extent of any refund of Taxes received by Landlord as a result of such Tax Protest or Tax Proceeding). If Landlord shall file such a Tax Protest or commence such a Tax Proceeding, as the case may be, at Tenant s request in accordance with the requirements of this Section

4.2.1(vi), Landlord shall not settle or compromise such Tax Protest or Tax Proceeding without the prior consent in writing of Tenant, which consent shall not be unreasonably withheld, conditioned or delayed. Upon Tenant s request, Landlord shall endeavor to provide Tenant with a copy of any notice of the assessed valuation of the Property and/or the Building received by Landlord, as well as copies of all tax bills and tax notices received by Landlord, and copies of all papers filed by Landlord in connection with any such Tax Protest or Tax Proceeding. Tenant s rights under this Section may be exercised only if Tenant is not in default of any term or condition of this Lease beyond the expiration of any applicable notice and cure period and only in respect of tax years occurring subsequent to the Term Commencement Date and which end prior to the Term Expiration Date. Notwithstanding the foregoing, during the last three (3) years of the Term (including any extension thereof, whether by exercise of an Extension Option or pursuant to the mutual agreement of Landlord and Tenant), if Landlord in good faith believes that a Tax Protest may result in an increase in the Taxes and so notifies Tenant within fifteen (15) days of receipt of a Tenant s Tax Protest Notice, then Tenant shall have no right to require that Landlord pursue a Tax Protest.

4.2.2. TENANT S COSTS OF ELECTRICITY. Tenant shall either pay directly to the utility provider when first due, or pay to Landlord, as Additional Rent, Tenant s costs of electricity supplied to the Premises or Property as metered, submetered or otherwise estimated in good faith by Landlord. Unless paid directly to the utility provider, starting on the Term Commencement Date, Tenant s costs of electricity shall be payable to Landlord in equal estimated monthly installments on the first day of each month together with the payment of Base Rent, subject to readjustment from time to time (but not more than once per calendar year) when the actual cost of electricity is determined or as of calendar year end, as determined by Landlord in its discretion. Any shortage shall be due and payable by Tenant within thirty (30) days of written notice by Landlord, and any excess shall be credited against any future Additional Rent obligations of Tenant, or refunded after the Lease Term has ended and the Tenant has no further obligations to Landlord.

4.2.3. OPERATING COSTS.

(i) Tenant shall pay to Landlord as Additional Rent an amount equal to all of Landlord s Operating Costs. Landlord, at Landlord s option, shall either (a) bill Tenant following the end of such calendar year, which shall be payable by Tenant thirty (30) days after billing, or (b) notify Tenant that Tenant shall pay Landlord in equal estimated monthly installments on the first day of each month commencing on the first day of the month following Landlord s notice, together with the Base Rent, subject to readjustment from time to time (but not more than once per calendar year) when actual Operating Costs are determined or as of calendar year end, as determined by Landlord in its discretion. After readjustment, any shortage shall be due and payable by Tenant within thirty (30) days of demand by Landlord and, to the extent Tenant is not in default nor would be in default

but for the giving of notice, the passage of time or both, any excess shall be credited against future Additional Rent obligations, or if the Term of this Lease has ended and the Tenant has no further obligations to Landlord, refunded to Tenant. Landlord shall provide Tenant upon request with reasonable supporting documentation for the Operating Costs. Operating Costs shall include, without limitation, those costs of owning, managing, operating, maintaining, repairing, replacing, servicing, cleaning, insuring, air conditioning and heating the Premises and the Common Areas. Such costs shall be those which the Landlord deems to be reasonable and appropriate including, but not limited to, the following: all costs and expenses for personnel (and all costs and expenses related to such personnel) engaged by Landlord in connection with the Premises; services and utilities (excluding utility charges separately charged to Tenant in this Lease) provided to the Premises and other costs and expenses, whether expended or incurred of repairing (including but not limited to roof repairs and maintenance), lighting, cleaning, painting, removal of snow, sanding of ice, security, cleaning, waterproofing, maintaining (including, but not limited to, preventive maintenance) and improving the Premises and the Common Areas, including, without limitation, all amenities; costs of maintaining landscaping, walkways, roadways, parking lots at the Premises and the Common Areas; any assessments charged to Landlord on account of maintenance of Common Areas under reciprocal easement agreements or otherwise; costs for the use and service of water and sewer; payments under contracts for services; legal, accounting and other professional fees; management fees which may be a fixed fee or a percentage of rent, and may be extrapolated by Landlord for the Premises based on Tenant s actual rent; removing rubbish and debris; providing pest and vermin control; dumpsters and trash removal services; providing, maintaining, repairing and replacing of paving, curbs, walkways, landscaping, planters, roof, solar panels and associated equipment, walls, drainage, on-site water lines, sanitary sewer lines, storm water lines, electrical lines, boilers, building systems, including, without limitation, elevators, if any, and life safety systems, including, without limitation, all components of the sprinkler systems, and other equipment serving the Building or other portions of the Premises; and all surcharges, costs and expenses that may result from any environmental or other laws, rules, regulations, guidelines or orders. Any of the above activities and services, including, without limitation, management of the Premises, may be performed by Landlord or its affiliates. Notwithstanding the foregoing or anything to the contrary contained in this Lease, items required to be capitalized by Landlord s accountants pursuant to generally accepted accounting principles shall be amortized over the item s or asset s useful life on a straight-line basis over its applicable tax amortization period as determined by Landlord s accountants, and only the current portion thereof shall be included within Operating Costs.

(ii) Operating Costs for purposes of this Lease shall not include the following (but nothing herein shall affect Tenant s obligations and Landlord s rights to collect payment as set forth below and in other provisions of this Lease):

(a) Landlord s advertising and promotional expenditures for the Building and Landlord s Property;

(b) Landlord s interest and principal payments on any mortgage or mortgages on Landlord s Property;

(c) Ground rent or similar payments to a ground lessor, if any;

(d) Costs related to maintaining Landlord s existence as a corporation, partnership or other entity.

(e) Costs incurred that are reimbursed to Landlord from insurance proceeds, taking awards or other third-party sources;

(f) Wages, salaries and benefits paid to any persons above the grade of Senior General or Building Manager and their immediate supervisor;

(g) Costs for services, supplies or repairs (other than management fees as provided in subsection 4.4(a) above) paid to any related entity in excess of costs that would be payable in an arm s length or unrelated situation for comparable services, supplies or repairs;

(h) Costs incurred in connection with, remediation, removal, encapsulation or disposal of Hazardous Materials (as defined below) in violation of Environmental Requirements (as defined below) (but this provision, in all events, shall not affect Tenant s obligations under other Sections of this Lease or be deemed to include the cost of Landlord s consultant s review of Tenant s compliance with its obligations concerning Hazardous Materials and/or Hazardous Materials List, which cost shall be deemed an Operating Cost);

(i) The cost of replacing any base building HVAC units and ancillary equipment where such costs are incurred prior to the Required Completion Date; and

(j) The cost of capital improvements shall not be included in Operating Expenses except such costs as are for (1) items that are primarily for the purpose of reducing Operating Expenses in Landlord s good faith estimate based upon the manufacturer s specifications, (2) replacing, modifying and/or adding improvements or equipment mandated by any statutes, ordinances,

codes, laws, rules, regulations, orders and directives of any Governmental Agency (as defined below) which takes effect after the date of this Lease or as a result of any new interpretation adopted by governmental authorities after the date of this Lease and any repairs, disposals or removals necessitated thereby (including, but not limited to, the cost of complying with the Americans With Disabilities Act of 1990 (including the Americans with Disabilities Act Accessibility Guidelines for Building and Facilities), or (3) any other items necessary to carry out Landlord s maintenance, repair, replacement and other obligations under this Lease, provided, however, that Tenant shall not be responsible for any capital expenses not otherwise allowed pursuant to clauses (1) and (2) above costing in excess of One Hundred Thousand Dollars ($100,000.00) during the last three (3) years of the Term, including any extension thereof, whether by exercise of an Extension Option or pursuant to the mutual agreement of Landlord and Tenant. As used herein, Governmental Agency means and refers to the United States of America, the state in which the Property is located, any county, city, district, municipality or other governmental subdivision, court or agency or quasi-governmental agency having jurisdiction over the Property and any board, agency or authority associated with any such governmental entity, including the fire department having jurisdiction over the Property.

(iii) Insurance costs (which are part of Operating Costs) include the cost of insuring the entire Premises, including, without limitation, the Building and other improvements now or hereafter situated on the Premises and the Common Areas, and all operations conducted in connection therewith, with such policies, coverages and companies and in such limits as may be selected by Landlord, at Landlord s option, including, but not limited to, fire insurance with extended or with all-risk coverage, commercial general liability insurance covering personal injury, deaths and property damage with a personal injury endorsement covering false arrest, detention or imprisonment, malicious prosecution, libel and slander, and wrongful entry or eviction, worker s compensation insurance, environmental insurance, plate glass insurance, contractual liability insurance, fidelity bonds and rent loss insurance.

4.3. SECURITY DEPOSIT.

(a) Simultaneously with the execution and delivery of this Lease, Tenant shall deliver the Security Deposit to Landlord, which shall be in the form of an irrevocable letter of credit ( Letter of Credit ) in the amount set forth in Section 1.3 hereof, and which satisfies the conditions of this Lease.

(b) Such Letter of Credit must satisfy all of the following conditions: (i) the Letter of Credit must be in the form of Exhibit E hereto or in such other form as is

approved by Landlord in its sole and absolute discretion, with an expiration date not less than ninety (90) days after this Agreement terminates or expires; (ii) the beneficiary of the Letter of Credit must be Landlord or Landlord s designee; (iii) the Letter of Credit must be irrevocable, unconditional and transferable one or more times without charge; (iv) the Letter of Credit must be issued by a bank satisfactory to Landlord in its sole and absolute discretion; (v) the Letter of Credit must provide that it may be drawn at a location in Boston, Massachusetts or another location acceptable to Landlord, and (vi) the Letter of Credit must be in a form approved by the Mortgagee (as hereinafter defined) in its reasonable discretion. If, at any time, the issuer of the Letter of Credit gives notice of its election not to renew, extend and/or reissue and/or not to honor the Letter of Credit, then Tenant shall, on or before thirty (30) days prior to the expiration of the term of the Letter of Credit, deliver to Landlord (1) a replacement Letter of Credit satisfying all of the above conditions or (2) cash in the full amount of the expiring Letter of Credit; and if Tenant fails to timely deliver to Landlord a replacement Letter of Credit as provided above or cash in the full amount of the expiring Letter of Credit, Landlord may draw on the Letter of Credit and hold and apply the proceeds of such drawing as the Security Deposit pursuant to the terms hereof. If (x) Landlord shall, in Landlord s sole discretion, feel insecure with the creditworthiness of the bank issuing the Letter of Credit and Tenant shall fail, within ten (10) days after notice, to either provide a replacement Letter of Credit as provided above or provide Landlord cash in the full amount of the existing Letter of Credit, or (y) Tenant fails to provide Landlord with cash in the full amount of the Letter of Credit within ten (10) days after (I) any proceedings under the Bankruptcy Code or any insolvency law are instituted with the bank as debtor or (II) the bank issuing the Letter of Credit is anticipated, in Landlord s reasonable opinion, to be taken over or is taken over by the Federal Deposit Insurance Corporation, the Resolution Trust Corporation or a similar entity, then such failure by Tenant under clauses (x) or (y) of this sentence shall constitute a default and, in addition to any other rights which Landlord might have by reason of such default, Landlord may draw on the Letter of Credit and hold and apply the proceeds of such drawing as part of the Security Deposit pursuant to the terms hereof. Tenant shall be responsible to pay Landlord for all actual out-of-pocket costs and expenses, including reasonable attorneys fees arising out of or related to a draw on the Letter of Credit. Subject to Landlord s right to require a replacement letter of credit as provided above if the Landlord shall hereafter feel insecure with the creditworthiness of Wells Fargo Bank, National Association, Landlord hereby approves the use of Wells Fargo Bank, National Association as the initial issuing bank for the Letter of Credit.

(c) The Security Deposit is security for the faithful performance and observance by Tenant of the terms, provisions and conditions of this Lease. It is agreed that in the event Tenant defaults in respect of any of the terms, provisions and conditions of this Lease or would be in default but for the passage of time or the giving of notice or both or if such passage of time or giving of notice is interrupted, stayed, barred or tolled by applicable law or legal proceeding or at the end of the Lease Term, Landlord may use, apply or retain the whole or any part of the Security Deposit without notice to Tenant and to the extent required for payment of any Base Rent, Additional Rent, or any other sum that is due Landlord or for any sum which Landlord may expend or may be required to expend pursuant to this Lease, including but not limited to any damage or deficiency accrued before or after summary proceedings or other re-entry by Landlord, including the

costs of such proceeding or re-entry and further including, without limitation, reasonable attorney s fees. It is agreed that Landlord shall always have the right to apply the Security Deposit, or any part thereof, as aforesaid, without notice and without prejudice to any other remedy or remedies which Landlord may have, or Landlord may pursue any other such remedy or remedies in lieu of applying the Security Deposit or any part thereof. No interest shall be payable on the Security Deposit, and Landlord has the right to commingle the Security Deposit with other funds of Landlord. If Landlord shall apply the Security Deposit in whole or in part, Tenant shall, upon demand, pay to Landlord the amount so applied to restore the Security Deposit to its original amount. Because Taxes, Operating Costs and other Additional Rent are subject to annual reconciliation based on actual amounts (together with all other amounts due from Tenant to Landlord, collectively referred to herein as Final Amounts Due ) determined to be due, in addition to the other rights provided herein to Landlord regarding the Security Deposit and notwithstanding anything to the contrary contained herein, Landlord shall have the right, in its sole discretion, upon the end of the Lease Term and Tenant s yield-up of the Premises in accordance with the terms of this Lease to hold all or a portion of the Security Deposit (or whatever amount remains after Landlord exercises its other rights hereunder), including, without limitation, drawing on a Letter of Credit, until ninety (90) days after the termination or earlier expiration of this Lease and Tenant yielding up the Premises pursuant and satisfying the other provisions of this Lease ( Outside Determination Date ), by which time (or an earlier date at Landlord s election), Landlord shall do the following: (i) if the Final Amounts Due are known, Landlord shall deduct the Final Amounts Due from the remaining Security Deposit and return any balance of the Security Deposit to Tenant, and (ii) if the Final Amounts Due are not known Landlord shall estimate the Final Amounts Due by the Outside Determination Date and deduct the Final Amounts Due from the remaining Security Deposit, with any adjustments to be made once the Final Amounts due are determined. If the remaining Security Deposit, if any, is not sufficient to pay Tenant s obligations hereunder, Tenant shall pay the same within ten (10) days of billing from Landlord. In the event of a sale or other transfer of Landlord s Property, or leasing of the entire Landlord s Property including the Premises subject to Tenant s tenancy hereunder, Landlord shall transfer the Security Deposit then remaining to the purchaser or other transferee and Landlord shall thereupon be released from all liability for the return of such Security Deposit to Tenant; and Tenant agrees to look solely to the new landlord for the return of the Security Deposit then remaining. The holder of any mortgage upon Landlord s Property shall never be responsible to Tenant for the Security Deposit or its application or return unless the Security Deposit shall actually have been received in hand by such holder. Tenant further covenants that it will not assign or encumber or attempt to assign or encumber the Security Deposit and that neither Landlord nor its successors or assigns shall be bound by any such assignment, encumbrance, attempted assignment or attempted encumbrance. This Section shall survive the expiration or earlier termination of this Lease.