DESIGN OF A PERFUSION SYSTEM FOR PHYSIOLOGICAL PREPARATIONS TO CONSERVE HIGH-MOLECULAR-WEIGHT REAGENTS

A perfusion system was designed for the purpose of conserving reagents and/or limiting the quantities of hazardous materials generated durin g in vitro electrophysiological experiments. The apparatus consisted o f a stirred cell assembly and an, appropriate size-exclusion filter to combine a recirculating flow with a continuous flow of substance-free solution. The system was able to achieve a rapid exchange of solution in the recording chamber without loss of the high molecular weight te st substances, botulinum toxin B or an IgG immunocomplex, over a 4-h p eriod of perfusion. Selective filtration was accomplished by directing a continuous influx of fresh solution to the stirred cell to clear lo w molecular weight components, while incorporating a 100-kDa cut off f ilter in the efflux-to-waste flow to retain the desired high molecular weight substances. Adsorption of these substances to the filter and a ssembly was minimized by use of a low, protein binding filter and incl usion of 0.1 mg/mL bovine serum albumen.