X0306 4 2014-08-12 0 0001492674 T2 Biosystems, Inc. TTOO 0001299790 Flagship Ventures Fund 2004 L P ONE MEMORIAL DRIVE 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001503559 Flagship Ventures Fund IV, L.P. ONE MEMORIAL DRIVE 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001400249 Flagship Ventures General Partner LLC C/O FLAGSHIP VENTURES ONE MEMORIAL DRIVE, 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001508051 Flagship Ventures Fund IV General Partner LLC ONE MEMORIAL DRIVE 7TH FLOOR CAMBRIDGE MA 02142 0 0 1 0 0001222012 AFEYAN NOUBAR 1 SUNSET RIDGE LEXINGTON MA 02173 0 0 1 0 0001255927 KANIA EDWIN M JR 0 0 1 0 Common Stock 2014-08-12 4 C 0 1632816 0 A 1632816 I See footnote Common Stock 2014-08-12 4 C 0 741755 0 A 2374571 I See footnote Series A-1 Convertible Preferred Stock 0 2014-08-12 4 C 0 128567 0 D Common Stock 75627 0 I See footnote Series A-2 Convertible Preferred Stock 0 2014-08-12 4 C 0 774527 0 D Common Stock 455604 0 I See footnote Series B Convertible Preferred Stock 0 2014-08-12 4 C 0 1053201 0 D Common Stock 619530 0 I See footnote Series C Convertible Preferred Stock 0 2014-08-12 4 C 0 819493 0 D Common Stock 482054 0 I See footnote Series D Convertible Preferred Stock 0 2014-08-12 4 C 0 629851 0 D Common Stock 370500 0 I See footnote Series E Convertible Preferred Stock 0 2014-08-12 4 C 0 631133 0 D Common Stock 371254 0 I See footnote The preferred stock is convertible at any time, at the holder's election and has no expiration date. The preferred stock automatically converted into common stock upon the closing of the Issuer's initial public offering. Held by Flagship Ventures Fund 2004, L.P. ("Flagship 2004"). Flagship Ventures General Partner LLC ("Flagship LLC") is the general partner of Flagship 2004. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship LLC. Flagship LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship 2004. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein. Held by Flagship Ventures Fund IV, L.P. ("Flagship IV"). Flagship Ventures Fund IV General Partner LLC ("Flagship IV LLC") is the general partner of Flagship IV. Noubar B. Afeyan, Ph.D. and Edwin M. Kania, Jr. are the managers of Flagship IV LLC. Flagship IV LLC and each of these individuals may be deemed to share voting and investment power with respect to all shares held by Flagship IV. Each of the filing persons disclaims beneficial ownership of the shares except to the extent of his or its pecuniary interest therein. FLAGSHIP VENTURES FUND 2004, L.P. By: Flagship Ventures General Partner LLC By: /s/ Noubar B. Afeyan, Ph.D., Manager 2014-08-13 FLAGSHIP VENTURES FUND IV, L.P. By: Flagship Ventures Fund IV General Partner LLC By: /s/ Noubar B. Afeyan, Ph.D., Manager 2014-08-13 FLAGSHIP VENTURES GENERAL PARTNER LLC By: /s/ Noubar B. Afeyan, Ph.D., Manager 2014-08-13 FLAGSHIP VENTURES FUND IV GENERAL PARTNER LLC By: /s/ Noubar B. Afeyan, Ph.D., Manager 2014-08-13 /s/ Noubar B. Afeyan, Ph.D. 2014-08-13 /s/ Edwin M. Kania Jr. 2014-08-13