Transforming Diagnostics, Patient Care & Economics September 2017 (NASDAQ: TTOO) Forward-Looking Statements This presentation contains forward-looking statements. Such statements reflect the current views of senior manag

Transforming Diagnostics, Patient Care & Economics September 2017 (NASDAQ: TTOO)

Forward-Looking Statements

This presentation contains forward-looking statements. Such statements reflect the current views of senior management of T2 Biosystems, Inc. ( we ,

us , our , T2 , T2 Biosystems or the Company ) and include those about T2 s goals, strategies, plans, objectives, prospects, milestones, future operations, business and industry,

anticipated product benefits, future events and conditions and potential scenarios. Such statements and those that include the words expect, intend, plan, believe, project,

forecast, estimate, may, should, anticipate and similar statements of a future or forward-looking nature identify forward-looking statements for purposes of the federal securities laws or

otherwise. Forward-looking statements address matters that involve risks and uncertainties. Each forward-looking statement is subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in

such statement, including, for example: (i) our status as an early commercial-stage company and expectation to incur losses in the future; (ii) our ability to obtain marketing authorization from the FDA or regulatory clearance for

additional product candidates in the United States or abroad; (iii) the market acceptance of our technology; (iv) our ability to timely and successfully develop and commercialize existing and future product candidates; (v) our lengthy

and variable sales cycle and lack of sales history; (vi) our ability to successfully manage growth; (vii) federal, state and foreign regulatory requirements; (viii) our uncertain future capital needs and ability to raise future

capital; (ix) dependence on third parties; (x) recruiting, training and retaining key personnel; (xi) competitive factors; (xii) manufacturing and other product risks; (xii) risks related to intellectual property; and

(xiii) other risk factors included in our annual report on form 10-K filed with the Securities and Exchange Commission (SEC) on March 15, 2017 and other documents we file with the SEC from time to

time. Accordingly, there are or will be important factors that could cause our actual results to differ materially from those indicated in these statements. The statements made herein speak only as of the date of this presentation. We do not

undertake, and specifically disclaim, any obligation to update any forward-looking statements contained in this presentation.

Transforming Diagnostics, Patient

Care & Economics | 2

Transforming Diagnostics, Patient Care & Economics

A platform technology with multiple, billion-dollar franchise opportunities

Innovative $3B+ Initial market technology with potential broad applications

Provide species-specific results, direct from whole blood,

Products covered by existing reimbursement

A new generation of diagnostics

High-risk patient access growing and several collaborations established

1. Mylonakis, E., Clancy, C. J., Ostrosky-Zeichner, L., Garey, K. W., Alangaden, G. J., Vazquez, J. A., ... & Zervou, F. N. (2015). T2 magnetic resonance assay for the rapid

diagnosis of candidemia in whole blood: a clinical trial. Clinical Infectious Diseases, ciu959.

Transforming Diagnostics, Patient Care & Economics | 3

T2MR: Establishing a New Standard in Sepsis Pathogen Detection T2Sepsis diagnostics provide a faster and more

accurate solution for sepsis pathogen detection >90% Detected1 Species-Specific Results Enables Targeted Therapy 3 to 5 hours Direct to T2Dx 1 to 48 VS. HOURS Species Identification (PCR, MALDI-TOF,

FilmArray, Verigene) All Require Positive Blood Culture 1 to 5 days Blood Culture 50-65% Detected2,3 1. Mylonakis, E., Clancy, C. J., Ostrosky-Zeichner, L., Garey, K. W., Alangaden, G. J., Vazquez, J. A., ...

& Zervou, F. N. (2015). T2 magnetic resonance assay for the rapid diagnosis of candidemia in whole blood: a clinical trial. Clinical Infectious Diseases, ciu959. 2. Clancy, C. J., & Nguyen, M. H. (2013). Finding the missing 50%

of invasive candidiasis: how nonculture diagnostics will improve understanding of disease spectrum and transform patient care. Clinical infectious diseases, 56(9), 1284-1292. 3. Cockerill III, F. R., Wilson, J. W., Vetter, E. A., Goodman, K. M.,

Torgerson, C. A., Harmsen, W. S., ... & Wilson, W. R. (2004). Optimal testing parameters for blood cultures. Clinical Infectious Diseases, 38(12), 1724-1730. Transforming Diagnostics, Patient Care & Economics | 4

Product Pipeline Highlights Enabled by Highly-Sensitive Detection Directly from whole blood no

requirement for blood culture 2016 2017 2018 and beyond1 T2Candida Panel T2Candida Panel FUNGAL CE & IVD Including pan-Candida T2Bacteria Panel T2Bacteria Panel BACTERIAL Including additional bacteria CE SEPSIS targets T2GNR1 BACTERIAL Gram

Neg Resistance RESISTANCE Markers TICK-BORNE 1. This slide contains T2 s future goals and aspirations, which constitute forward-looking statement that are subject to risks and uncertainties that could cause actual results to differ materially

from those expressed or implied by such statement. See Forward-Looking Statements on slide 2. Transforming Diagnostics, Patient Care & Economics | 5

T2MR Featured at Tradeshows and in Over 200 Publications Worldwide T2Candida 91.1% Sensitivity 99.4%

Specificity LoD 1-3 CFU/mL T2Candida 96.4% Sensitivity 99.4% Specificity T2Candida featured as sensitive and specific diagnostic test for invasive candidiasis T2Candida projected to reduce deaths 60%

and to save each site $5.8M/yr T2MR detected Lyme Disease-causing bacteria in blood T2Candida Customers present cost savings and superiority to blood culture T2Candida Customers present cost savings, LOS savings, and decreased time to

appropriate antifungal therapy T2Candida Customers present antifungal savings, improved care, and preliminary study on predicting patient outcomes. T2Bacteria Early experience with performance evaluations in Europe. T2Sepsis Solution

Customers present stewardship benefits of T2Candida and early experience with T2Bacteria RUO Transforming Diagnostics, Patient Care & Economics | 6

Shortcomings of Sepsis Management Transforming Diagnostics, Patient Care & Economics | 7

The Facts About Sepsis Most expensive hospital-treated condition in the U.S. Contributes to 1 in 2-3 hospital deaths1 Representing $27B in U.S. healthcare $ costs2,3 Claims more lives annually than breast cancer, prostate cancer and AIDS, combined4 More than 1 in 5 surviving patients die within 2 years as a

consequence of sepsis5 More than 1.6M diagnosed annually in the U.S. and ~500,000 die6 Sepsis is the most prevalent and costly cause of hospital readmissions7 1. Liu, V., Escobar, G. J., Greene, J. D., Soule, J., Whippy, A., Angus, D. C., &

Iwashyna, T. J. (2014). Hospital deaths in patients with sepsis from 2 independent cohorts. Jama, 312(1), 90-92. 2. Torio, C. M., Moore, B. J. (2016). Statistical Brief# 204. Healthcare Cost and Utilization

Project (HCUP). May. 3. McDermott, K. W., Elixhauser, A., Sun, R. (2017). Statistical Brief# 225. Healthcare Cost and Utilization Project (HCUP). June. 4. National Institute of General Medical Sciences. National Institutes of Health. Sepsis fact

sheet. 2014. 5. Prescott, H. C., Osterholzer, J. J., Langa, K. M., Angus, D. C., & Iwashyna, T. J. (2016). Late mortality after sepsis: propensity matched cohort study. BMJ, 353, i2375. 6. Elixhauser, A., Friedman, B., Stranges, E. (2011).

Statistical Brief# 122. Healthcare Cost and Utilization Project (HCUP). October. 7. Mayr, F. B., Talisa, V. B., Balakumar, V., Chang, C. C. H., Fine, M., & Yende, S. (2017). Proportion and cost of unplanned

30-day readmissions after sepsis compared with other medical conditions. Jama, 317(5), 530-531. Transforming Diagnostics, Patient Care & Economics | 8

Shortcomings of Current Sepsis Management The current process drives up healthcare costs and delays in

appropriate treatment 1 6+ Days for Diagnostic Results Overuse of Antimicrobial Therapies False Negative Results Quality Metrics Impact Multi-Step, Labor-Intensive Process Transforming Diagnostics, Patient Care & Economics | 9

Sepsis Management Today Empiric therapy dominates treatment decisions because of the time delay of blood

culture Accelerate Diagnostics BioM rieux BD Bruker BioFire Luminex 0 Hours 24 72 Hours 72 120 Hours ~27 Hours Patients Identified Some Blood Culture Positive Final

Positive & Negative Blood7 Days Testing Process Blood Samples Taken Results CompletedCulture Results CompletedPatient On The Right Drug > 1 48 Hours: Species 1 5 Days Blood Culture

Growth > Once Positive Identification Patient Placed on Patient Migrated Patient migrated to Blood culture-based Broad Spectrum to Alternative Antifungals species Dx available

Treatment Process Antibiotics Antibiotics Test Methods Reliance on Empiric Therapy Blood Culture Only Subject to Limits Delay In Diagnosis Due to Blood Culture Growth 50-65% Sensitive Limitations of Blood Culture Transforming Diagnostics, Patient Care & Economics | 10

T2Sepsis Solution Transforming Diagnostics, Patient Care & Economics | 11

T2Sepsis Solution1: Rapidly Detecting Species Not Covered by First Line Empiric Therapy 30% Ineffectively

treated bacterial infections Up to 60% 95% Ineffectively treated effective Rx effective initial 10% fungal infections In hours3 empiric Rx2 T2Candida Panel % Mortality4 T2Bacteria Panel % Mortality C.

albicans 30% S. aureus 25%5 C. tropicalis 41% E. faecium 36%6 C. parapsilosis 23% K. pneumoniae 42%7 C. glabrata 31% P. aeruginosa 39%5 C.

krusei 40% A. baumannii 50%8 E. Coli 22%5 Combined with first line empiric therapy, T2MR may enable clinicians to appropriately treat up to 95% of septic patients in hours 1. The T2Sepsis SolutionTM combines the preferred

standard of care for the management of sepsis patients with T2 Biosystems products, including the T2Dx Instrument and T2Candida Panel, and the T2Bacteria Panel, which is commercially available in Europe and other countries that

accept the CE mark and available for research use only in the US 2. Buehler, S. S., Madison, B., Snyder, S. R., Derzon, J. H., Cornish, N. E., Saubolle, M. A., ... & Wolk, D. M. (2016). Effectiveness of practices to increase timeliness of

providing targeted therapy for inpatients with bloodstream infections: a laboratory medicine best practices systematic review and meta-analysis. Clinical microbiology reviews, 29(1), 59-103. 3. Kumar, A.,

Ellis, P., Arabi, Y., Roberts, D., Light, B., Parrillo, J. E., ... & Peters, C. (2009). Initiation of inappropriate antimicrobial therapy results in a fivefold reduction of survival in human septic shock. CHEST Journal, 136(5), 1237-1248. 4.

Andes, D. R., Safdar, N., Baddley, J. W., Playford, G., Reboli, A. C., Rex, J. H., ... & Kullberg, B. J. (2012). Impact of treatment strategy on outcomes in patients with candidemia and other forms of invasive candidiasis: a patient-level

quantitative review of randomized trials. Clinical Infectious Diseases, 54(8), 1110-1122. 5. Wisplinghoff, Hilmar, et al. Nosocomial bloodstream infections in US hospitals: analysis of 24,179 cases from a prospective nationwide surveillance

study. Clinical infectious diseases 39.3 (2004): 309-317. 6. Suppli, M., Aabenhus, R., Harboe, Z. B., Andersen, L. P., Tvede, M., & Jensen, J. U. (2011). Mortality in enterococcal bloodstream

infections increases with inappropriate antimicrobial therapy. Clinical Microbiology and Infection, 17(7), 1078-1083. 7. Tumbarello, M., Viale, P., Viscoli, C., Trecarichi, E. M., Tumietto, F., Marchese, A., ... & Losito, A. R. (2012).

Predictors of mortality in bloodstream infections caused by Klebsiella pneumoniae carbapenemase producing K. pneumoniae: importance of combination therapy. Clinical Infectious Diseases, 55(7), Transforming 943-950. Diagnostics, Patient

Care & Economics | 12 8. Alsan, M., & Klompas, M. (2010). Acinetobacter baumannii: an emerging and important pathogen. Journal of clinical outcomes management: JCOM, 17(8), 363. T2Bacteria is for investigational use only. Product is not

FDA-cleared for clinical use.

Faster Therapy Saves Lives and Healthcare Costs1 Current Situation Day Day Day Day Day Day 2 1 3 4 5 6 Septic

Deaths 9,615 people die a week $519,230,769 each week Healthcare costs of care $ $ $ $ $ $ $ $ $ $ 1. Represents the potential healthcare savings and lives saved using the T2Sepsis Solution to test high risk patients based on assumed levels of total

annual patients assuming all high-risk sepsis patients are tested with T2Sepsis and assuming (i) ultimate regulatory approval for T2Bacteria, (ii) 95% of high risk patients receive appropriate therapy within hours of the presentation of

symptoms, (iii) a 50% mortality rate reduction for patients who receive rapid appropriate therapy, and (iv) that each new detected patient saves $22,800. This slide contains T2 s estimates, which are not based on historical results

and constitute forward-looking statements that are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statement. See Forward-Looking Statements on slide 2.

Potential: If all high-risk patients are tested with the T2Sepsis Solution 3 to 5 Hours 1,666 lives saved a week Lives Saved Healthcare savings $ $ $ $ $ 253,211,538 weekly hospital savings Transforming Diagnostics, Patient Care &

T2Bacteria Panel Designed to rapidly identify six of the most deadly and prevalent bacteria species often not

covered by initial empiric therapy $1.5B+ Market Opportunity FDA Filing, September 2017 CE Mark, July 2017 Completed pivotal study in 11 hospitals sites testing 1,700+ patient samples Sensitivity: 95.8% Specificity: 98.1% 63 samples T2+/BC- where additional culture was positive for organism identified by T2Bacteria Established DRG and CPT reimbursement codes CPT codes enable reimbursement of ~$290 for patients not admitted Recently established

Research Use Only (RUO) program in place with 5 customers under contract Existing commercial organization will launch into existing T2Candida customer base, if cleared by FDA1 1. Represents T2 s future goals and aspirations, which constitute

forward-looking statement that are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statement. See Forward-Looking Statements on slide 2. Transforming

Diagnostics, Patient Care & Economics | 14

T2Bacteria Addresses Large Unmet Market Need No FDA-cleared technology

that can derive species-specific results directly from blood Bacteria: The Facts ~15,000,000 U.S. patients tested for blood stream infections annually1 8.75M Patients at high risk for a bacterial infection1 Each hour of delayed treatment increases

mortality risk nearly 8%2 60% Patients have effective initial empiric therapy3 50-60% Sepsis episodes are diagnosed in the ED4 ~50% Reduction in mortality with rapid detection and appropriate treatment5

T2Bacteria designed to detect ~70% of community-acquired infections in the ED6 1. Market Research conducted by T2. 2. Kumar, A., et al, (2006). Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant

of survival in human septic shock. Critical care medicine, 34(6), 1589-1596. 3. Buehler, S. S., et al., (2016). Effectiveness of practices to increase timeliness of providing targeted therapy for inpatients with bloodstream infections: a laboratory

medicine best practices systematic review and meta-analysis. Clinical microbiology reviews, 29(1), 59-103. 4. Garnacho-Montero, J., et al (2015). Adequate antibiotic therapy prior to ICU admission in patients

with severe sepsis and septic shock reduces hospital mortality. Critical care, 19(1), 302. 5. Leibovici, L., Shraga, I., Drucker, M., Konigsberger, H., Samra, Z., & Pitlik, S. D. (1998). The benefit of appropriate empirical antibiotic treatment

in patients with bloodstream infection. Journal of internal medicine, 244(5), 379-386. 6. Luzzaro, F., et al. 2002). Prevalence and drug susceptibility of pathogens causing bloodstream infections in northern

Italy: a two-year study in 16 hospitals. European journal of clinical microbiology and infectious diseases, 21(12), 849-855. Transforming Diagnostics, Patient

Care & Economics | 15

T2Bacteria Clinical Trial Overview1 98.1% 95.8%

Overall Sensitivity Overall Specificity

Sensitivity by Test Specificity by Test

A. baumannii 97.5% (39/40)87.1%-99.6%

E. coli 90.9% (30/33)76.4%-96.9%

faecium 100.0% (41/41) 91.4% 100.0%

K. pneumoniae 100.0% (46/46) 92.3% 100.0%