HARVARD BIOSCIENCE INC

Evaluation of Disclosure Controls and Procedures

Under the supervision of our Chief Executive Officer and Chief Financial Officer, we evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) as of June 30, 2025.

Disclosure controls and procedures are designed to ensure that information required to be disclosed in our reports filed or submitted under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include controls and procedures designed to ensure that information required to be disclosed in our reports filed under the Exchange Act is accumulated and communicated to management, including our Chief Executive Officer and Chief Financial Officer, to allow timely decisions regarding required disclosure. As described below, we previously identified material weaknesses in our internal control over financial reporting. Solely as a result of these material weaknesses, our Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were not effective as of June 30, 2025.

Previously Reported Material Weaknesses

As reported in Part II, Item 9A. “Controls and Procedures” of our Annual Reports on Form 10-K for the year ended December 31, 2024, we identified material weaknesses in our internal control over financial reporting related to controls over (i) our order to cash cycle and (ii) our physical count of inventories. Specifically, we did not design and maintain effective manual controls over the processing and review of a substantial portion of our revenue transactions. Additionally, we did not design and maintain an effective cycle count program to verify quantities of inventories held at Company locations that account for a substantial portion of inventories. The timeliness, level of precision, and appropriate segregation of duties in our review processes over revenue transactions and our physical counts of inventories were not sufficient to prevent, detect, and correct potential misstatements in a timely manner.

While management, with oversight from the Audit Committee of our Board of Directors, has commenced implementing changes to our internal control over financial reporting in order to remediate the control deficiencies that resulted in the material weaknesses as previously disclosed in our Form 10-K for the fiscal year ended December 31, 2024, additional time is required to complete the material weakness remediation work. We expect to continue our efforts throughout fiscal year 2025. We believe that the implementation of the remediation plans disclosed under “Part II - Item 9A - Controls and Procedures” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, will allow us to address the deficient controls within our internal control environment, which will facilitate the remediation of the material weaknesses. The material weaknesses will not be considered remediated until management completes the design and implementation of the measures disclosed under “Part II - Item 9A - Controls and Procedures” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and the controls operate for a sufficient period of time such that the effectiveness of those changes is demonstrated with an appropriate amount of consistency and management has concluded, through testing, that these controls are effective. We also may conclude that additional measures may be required to remediate the material weaknesses or determine to modify the remediation plans.

Changes in Internal Control over Financial Reporting

Other than changes related to remediation of the material weaknesses, there were no changes in our internal control over financial reporting during the second quarter of fiscal 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Limitations on Effectiveness of Controls and Procedures

In designing and evaluating our controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives, and management is required to apply its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud within the Company have been detected.

**PART II. OTHER INFORMATION