Specialized Tools for Electrophysiology and Cell Biology Research

General Holder Information

Product Summary

Warner Instruments precision made holders are ideal for any applications which use fluid filled glass microelectrodes and micropipettes

  • Patch clamping
  • Intracellular and extracellular recording
  • Iontophoresis and ion specific measurements
  • Microinjection and Perfusion
  • Dual channel holders for Theta glass


  • Bored to fit glass OD
  • Straight, 45° and 90° body styles
  • Replaceable coupling elements
  • Customs designs available

Warner Instruments' precision made holders are ideal for any application which uses fluid filled glass microelectrodes and micropipettes. They provide the important link between live cells and high impedance amplifiers in applications such as patch clamp recording, intracellular and extracellular recordings, iontophoresis and ion specific measurements. Non electrical micropipette holders are used for microinjection.

Our standard microelectrode holders are available in numerous choices of body style, electrical coupling, and ports and venting. We can also design and fabricate custom microelectrode holders for any specialized application. Call our sales department for further information.

Holder Materials
The highest quality materials are used in the fabrication of Warner electrode holders. Holder bodies and caps are machined from either acrylic or polycarbonate, and are annealed and vapor polished. Acrylic is generally preferred for its optical quality, which is particularly important for the detection of air bubbles in holders filled with electrolyte. Acrylic is the standard material for E, ME and MP Series Holders.

Q and PE Series Holders are most often used in patch clamp applications and are made from polycarbonate. Studies have shown that polycarbonate holders exhibit lower noise levels in these critical applications. Connector pins are gold-plated and connector insulators are made from PTFE or polycarbonate.

Body Styles
Holders that attach directly to a headstage are available with a choice of body style (position of the microelectrode relative to the headstage connector). Bodies may be straight (axial), right angle or 45° Straight holders are most often used, but in setups with multiple electrodes or other space limiting factors, a right angle or 45° holder may work better.

Glass Size
To insure a good fit, holders are bored for specific glass sizes. Standard bore sizes are 1.0, 1.2, 1.5, 1.7 and 2.0 mm, but any size between 1.0 and 2.0 mm may be specified. The bore is made 0.1 mm oversize to accommodate small variations in glass diameters. Tightening the threaded end cap compresses a silicone rubber gasket providing a good seal around the glass.

Headstage Connections
Competitively priced holders are available for virtually any commercially available headstages in use. This includes headstages made by Warner, Axon, Heka, List, Dagan and others.

Electrical Coupling
The electrical signal from the microelectrode is coupled to the headstage using one of three replaceable elements. These are:

Ag/AgCl Pellet
The molded pellet assembly is installed inside the holder. Both holder and pipette are filled with electrolyte before assembly and any trapped air bubbles removed. Holders with pellets are ready for use (no chloriding needed) and provide small offset potentials and low drift. E and ME Series holders are available with pellets.

Ag Wire
Silver wire holders are generally used for patch clamp recording or measurements with ion selective electrodes where only the pipette is filled. The silver wire extends approximately 25 to 30 mm from the end of the holder to be inserted into the pipette. The portion of the wire in contact with the electrolyte must be chlorided before use. Ssilver wire couplings are available with any Warner microelectrode holder.

Q Series holders are available with the hybrid coupling. The hybrid coupling combines the advantages of a Ag/AgCl pellet (no chloriding) and a Ag wire. A 1 mm diameter Ag/AgCl pellet sits at the end of a 70 mm long Ag wire. The wire is insulated with PTFE tubing and sealed with wax. The pellet end is inserted into the fluid filled microelectrode. Hybrid couplings can only be used with straight body (Q Series) holders and glass tubing with an ID greater than 1 mm.

Port or Vent
All holders can include a port to apply pressure or suction or a vent to equalize internal pressure. Standard ports are 2 mm diameter (polycarbonate) for connection to 1/16" ID tubing. Stainless steel ports are available by special order. Vents are 0.8 mm diameter holes in place of the port. Micropipette holders designed specifically for pressure injection are offered with a selection of ports including male and female Luer.

Pressure Models
h e ME and MP Series holders are designed for applying pressure or suction to the electrode or pipette. The ME Series are microelectrode holders with either a Ag/AgCl pellet or Ag wire coupling. MP Series are non-electrical for pressure injection only.

Theta Glass Holders
The THS Series holders accommodate the use of theta glass.

Special Designs
Even with our large selection of holders, we realize that your particular application may require something slightly different. Fortunately, our holder designs are easily modified and we welcome your inquiries. Please call our tech support department and we'll be happy to discuss your particular needs.

In general:

E Series Holders are for intracellular recording, extracellular recording, and microintophoresis
Q Series Holders are for patch clamp and intracellular recording
PE Series Holders are for patch clamp microperfusion (perfusing at the pipette tip)
ME Series Holders are for pressure applications
MP Series Holders are for non-electrical pressure applications
THS Series Holders are for theta glass

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