The movement of electrodes during patch clamp recording is undesirable but often occurs during changes in pipette pressure. This is most noticeable when applying suction in order to rupture the patch of membrane beneath a cell-attached electrode to enable whole-cell recording. The design of our electrode holders greatly reduces the chance of such movement by supporting the electrode at 2 points. This enables protracted recordings with excellent mechanical stability.
Our microelectrode holders have been designed to work with Axon Instruments and HEKA Co. headstages and offer electrophysiologists holders with excellent mechanical stability and low noise. They have been recommended by both Axon and Burleigh Instruments for long term recording and stability.
An important consideration, aside from mechanical stability, is the electrical noise added by the holder. Our holders are primarily constructed of polycarbonate as this exhibits lower electrical noise than acrylic. When noise is measured from the panel meter of an Axopatch 200A (CV201A or CV201AU headstages in capacitance mode, 30Hz-5kHz-3dB, 4-pole Butterworth; Axon Instruments) the noise added by the original DB series holders is comparable to that added by Axon Instruments HL-1 or HL-U holders.
All our holders are supplied with gold-plated pins for good conductance and low noise.
The DB series electrode holders have been rigorously tested and used extensively for successful low noise, whole-cell and single-channel recording for over 10 years. In 2008 the DB series was improved to further reduce electrical noise and prevent 'creep' of the electrode cap over long recording times.
G23Instruments' completely new (September 2009) ISO range of electrode holders, offers major improvements over the original DB range that virtually eliminate pipette movement and air leakage. A longer barrel allows for the insertion of a small polycarbonate cylinder between the two O-rings which keeps everything rigid. The cylinder is precision milled at both ends to hold the O-rings in place.
Over 2 years in development, this new design offers electrophysiologists a holder with the highest mechanical stability and low noise.
The microelectrode holders designed for use with the HEKA Co. amplifiers come equipped with a BNC connector to fit the headstages of the patch clamp amplifiers EPC-10, EPC-9, EPC-8, EPC-7 or potentiostat PG 300. The BNC connector is specially made and is competely rigid with the rest of the holder so that movement of the holder is practically eliminated once connected to the headstage. The extra long specially made gold plated pin is designed such that your wire connection requires no soldering, as in our other holders.