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 during in vitro electrophysiological experiments. The apparatus consisted of 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 test substances, botulinum toxin B or an IgG immunocomplex, over a 4-h period of perfusion. Selective filtration was accomplished by directing a continuous influx of fresh solution to the stirred cell to clear low molecular weight components, while incorporating a 100-kDa cutoff filter in the efflux-towaste flow to retain the desired high molecular weight substances. Adsorption of these substances to the filter and assembly was minimized by use of a low protein binding filter and inclusion of 0.1 mg / mL bovine serum albumen.