HARVARD BIOSCIENCE INC 10-Q

Item 5. Other Information. None of our directors or executive officers adopted or terminated a Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement (as defined in Item 408(c) of Regulation S-K) during the quarterly period covered by this report. Item 6. Exhibits. 3.1 Second Amended and Restated Certificate of Incorporation of Harvard Bioscience, Inc. (previously filed as an exhibit to the Company’s Registration Statement on Form S-1/A (File No. 333-45996) (filed November 9, 2000) and incorporated by reference thereto). 3.2 Certificate of Amendment to Second Amended and Restated Certificate of Incorporation of Harvard Bioscience, Inc. (previously filed as an exhibit to the Company’s Current Report on Form 8-K (filed March 6, 2026) and incorporated by reference thereto). 3.3 Amended and Restated By-laws of Harvard Bioscience, Inc. (previously filed as an exhibit to the Company’s Registration Statement on Form S-1/A (File No. 333-45996) (filed November 9, 2000) and incorporated by reference thereto). 3.4 Amendment No. 1 to Amended and Restated Bylaws of Harvard Bioscience, Inc. (as adopted October 30, 2007) (previously filed as an exhibit to the Company’s Current Report on Form 8-K (filed November 1, 2007) and incorporated by reference thereto). 3.5 Amendment No. 2 to Amended and Restated Bylaws of Harvard Bioscience, Inc. (as adopted January 19, 2026) (previously filed as an exhibit to the Company’s Current Report on Form 8-K (filed January 20, 2026) and incorporated by reference thereto). 10.1 Employment Agreement by and between Harvard Bioscience, Inc. and John Duke, dated March 6, 2026 (previously filed as an exhibit to the Company’s Current Report on Form 8-K (filed March 10, 2026) and incorporated by reference thereto). 10.2 Employment Agreement by and between Harvard Bioscience, Inc. and Mark Frost, dated March 6, 2026 (previously filed as an exhibit to the Company’s Current Report on Form 8-K (filed March 10, 2026) and incorporated by reference thereto). 31.1 Certification of Chief Financial Officer of Harvard Bioscience, Inc., pursuant to Rules 13a-14(a) and 15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 31.2 Certification of Chief Executive Officer of Harvard Bioscience, Inc., pursuant to Rules 13a-14(a) and 15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 32.1* Certification of Chief Financial Officer of Harvard Bioscience, Inc., pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 32.2* Certification of Chief Executive Officer of Harvard Bioscience, Inc., pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 101.INS Inline XBRL Instance Document 101.SCH Inline XBRL Taxonomy Extension Schema Document 101.CAL Inline XBRL Taxonomy Extension Calculation Linkbase Document 101.DEF Inline XBRL Taxonomy Extension Definition Linkbase Document 101.LAB Inline XBRL Taxonomy Extension Labels Linkbase Document 101.PRE Inline XBRL Taxonomy Extension Presentation Linkbase Document 104 Cover Page Interactive Data File (formatted in Inline XBRL and contained in Exhibit 101) * This certification shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, or otherwise subject to the liability of that section, nor shall it be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Securities Exchange Act of 1934 23 Table of Contents SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by undersigned thereunto duly authorized. HARVARD BIOSCIENCE, INC. Date: May 12, 2026 By: /s/ JOHN DUKE John Duke Chief Executive Officer By: /s/ MARK FROST Mark Frost Chief Financial Officer 24