Pressure-polishing pipettes for improved patch-clamp recording.
Pressure-polishing is a method for shaping glass pipettes for patch-clamp recording. We first developed this method for fabricating pipettes suitable for recording from small (<3 m) neuronal cell bodies. The basic principal is similar to glass-blowing and combines air pressure and heat to modify the shape of patch pipettes prepared by a conventional micropipette puller. It can be applied to so-called soft (soda lime) and hard (borosilicate) glasses. Generally speaking, pressure polishing can reduce pipette resistance by 25% without decreasing the diameter of the tip opening (Goodman and Lockery, 2000). It can be applied to virtually any type of glass and requires only the addition of a high-pressure valve and fitting to a microforge. This technique is essential for recording from ultrasmall cells (<5 m) and can also improve single-channel recording by minimizing pipette resistance. The blunt shape is also useful for perforated-patch clamp recording since this tip shape results in a larger membrane bleb available for perforation.
Johnson
Brandon E
BE
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
Brown
Austin L
AL
Goodman
Miriam B
MB
D000818:Animals; D005898:Glass; D006801:Humans; D008839:Microelectrodes; D009474:Neurons / Q000502:physiology; D018408:Patch-Clamp Techniques / Q000295:instrumentation* / Q000379:methods