The BC-535 Bilayer Clamp Amplifier is designed for recording single channel currents from planar lipid bilayers. The amplifier features an extremely low noise, resistive feedback head stage capable of measuring currents from sub-pA to 20 nA. Additional features include AutoZero, capacitance test, and capacitance compensation circuitry, as well as digital hold controls, audio output, and an internal Bessel filter.