The 65-0075 BSC-HT Haas Top is an interface-type chamber2 utilizing semi-submersion principles. It provides for rapid exchange of superfusing fluids, and excellent stability for intracellular recording. Slices rest on nylon mesh below which a thin sheet of the perfusate of interest flows. The bottom side of the slice is wetted as capillary action saturates the mesh. Slices are oxygenated by a warmed and humidified mixture of 95% O2 /5% CO2 which flows across the top surface of the slice. The BSC-HT has been designed such that, if desired, one can study the effects of two drugs simultaneously. One drug flows down the left portion of the chamber and the second down the right.

Laboratory results confirm that the semi-submersion top design has a good history of proven results:
• Maintains a stable intracellular membrane potential of more than 60 mV.
• Facilitates action potentials with overshoots close to 100 mV in amplitude, duration of less than 2 msec at 32°C, when used with hippocampal pyramidal and granular cells.
• Maintenance of the above potentials is possible for more than 1 hour undisturbed by changes in perfusion fluids.
• Preparation slices remain viable for up to 12 hours.
• Using flow rates of 1 ml/min, will completely exchange the chamber fluid in less than 1 minute.