Glass Microelectrodes and Tight Seals

 

Successful electrophysiological measurements depend on two technologies:

the design of electronic instrumentation

and

the properties and fabrication of glass micropipettes.

 

 

Glass pipettes are used both for intracellular recording and for patch recording; recently quartz pipettes were used for ultra low-noise single-channel recording. Successful patch recording requires a tight seal between the pipette and the membrane.

Although there is not yet a good molecular description of this seal, we can describe its electrical characteristics:

 

 

Requirement above states that the quality of the measurement depends on minimizing perturbation of the cells. For the case of voltage recording, this point can be presented with the voltage divider circuit.