Biomarkers are collected and used to determine biological propensities of a patient, to determine the efficacy of medical devices, to select and administer therapeutic agents, to select medical devices, to make adjustments to medical devices, and/or to adjust surgical techniques. An apparatus includes a port to draw a biological fluid (e.g., a mist) from a surgical site. The apparatus includes a sensor having a cantilevered beam. The beam includes substances selected to attract certain biomarkers as the fluid is communicated across the beam. The same apparatus or another apparatus is used to administer a therapeutic agent based at least in part on collected biomarker data. The therapeutic agent delivery apparatus may include a device that is also used to create a wound at a surgical site. For instance, a harmonic surgical instrument may be used to both collect biomarkers and administer a therapeutic agent (e.g., gene therapy using sonoporation).