COMPARISON OF RECOVERY AND DELIVERY IN-VITRO FOR CALIBRATION OF MICRODIALYSIS PROBES

One approach to calibrating a microdialysis probe in vivo is to determ ine the amount of a test compound that diffuses out of the membrane re lative to the amount in the perfusate (i.e., the probes delivery) and assume that the same relation exists for the amount of analyte that wi ll diffuse into the probe relative to the concentration in the sample (i.e., the probes recovery). This concept was systematically tested in vitro with a wide range of compounds, microdialysis probe configurati ons, dialysis membrane types, and solution conditions. Recovery was fo und to depend on the identity of the analyte, the type of dialysis mem brane, the membrane length, the perfusion flow rate, and the perfusate pH. Recovery was independent of the analyte concentration. No statist ically significant difference was found between the recovery and deliv ery of a given compound with a given probe under any of the conditions tested.