Two types of bipolar microelectrodes for intraretinal use.

This paper describes in some detail the construction of two types of bipolar microelectrodes that were used in intraretinal recordings from the intact rhesus monkey eye. The first type consists of a glass micropipette with a partly insulated silver paint coating, yielding a recording site located 120 micrometers from the tip of the glass pipette. The second type consists of two coaxial glass micropipettes with a tip distance of 50 micrometers and tip diameter of 10 and 1 micrometer, respectively. The coaxial glass electrode has a better electrical stability than the silver paint electrode and is mechanically stronger. An example of a recording is shown.