While the Axon 200B can be, and has been, used for bilayer measurements, it’s not exactly the ‘right tool for the job’. Basically, the 200B provides many features not needed for bilayer work, and lacks certain other features needed for the bilayer.

For example, you need to ask and answer three questions before incorporating your channel.

1. Do I have a membrane?
2. How large is it?
3. Is it stable?

Answers to these questions are most directly achieved by monitoring the membrane capacitance. pClamp’s method of measuring capacitance doesn’t work for bilayers and the 200B does not provide this service.

By comparison, Warner's BC-535 has a built-in capacitance measurement circuit with a digital readout.

As another example, it’s a great convenience to monitor membrane formation without having to take your eyes away while you’re working. The BC-535 incorporates an audio circuit just for this purpose. It makes one sound when you have an open hole and a different sound when you have a membrane. All you need do is listen for the sound to change when the membrane forms. You will truly find this a lot more useful than it sounds. No pun intended.

As a final point, the 200B provides Series R and whole cell compensation circuits at considerable expense. These circuits are not needed for bilayer work and so are not a part of the BC-535. This is one reason why the BC-535 costs about 50% that of the 200B while having virtually the same noise and bandwidth specifications.

But with all that said, the 200B can be used for bilayer work!