X0306 4 2019-09-11 0 0001123494 HARVARD BIOSCIENCE INC HBIO 0001197452 LOY BERTRAND C/O HARVARD BIOSCIENCE, INC. 84 OCTOBER HILL RD. HOLLISTON MA 01746 1 0 0 0 Common Stock 2019-09-11 4 P 0 15590 3.01 A 138674 D Common Stock 2019-09-12 4 P 0 11297 3.07 A 149971 D Common Stock 2019-09-13 4 P 0 7372 3.11 A 157343 D Common Stock 68466 I by The BZH Trust This transaction was executed in multiple trades at prices ranging from $2.93 to $3.10, inclusive. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. Includes (a) a deferred stock award of 6,600 restricted stock units which vest quarterly in equal installments on September 30, 2019 and December 31, 2019; (b) a deferred stock award of 35,100 restricted stock units which fully vest on the earlier of (i) the date of the Issuer's next Annual Meeting of Stockholders after May 16, 2019, immediately prior to the commencement of such meeting, and (ii) May 23, 2020; (c) a deferred stock award of 7,000 restricted stock units which vest quarterly in equal installments on September 30, 2019 and December 31, 2019; and (d) 89,974 shares of common stock held by the Reporting Person This transaction was executed in multiple trades at prices ranging from $2.97 to $3.14, inclusive. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. Includes the awards referenced in clauses (a) through (c) of footnote (2) above, plus 101,271 shares of common stock held by the Reporting Person. This transaction was executed in multiple trades at prices ranging from $3.04 to $3.14, inclusive. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. Includes the awards referenced in clauses (a) through (c) of footnote (2) above, plus 108,643 shares of common stock held by the Reporting Person. This form has been signed under power of attorney. /s/ Chad Porter, by power of attorney 2019-09-13