Advice from the Field — Plexon Probes Edition

• Some advice straight from current Plexon customers. If you would like to know more or have any further questions please contact one of our Plexon Sales Engineers.

What is the difference between U, V, and S probes?

• All three configurations are multi-use, multi-site linear electrodes, the difference being in their tips. The U-Probe is robust with a blunt tip angle and is most often used for acute studies with larger animals such as primates, while the S-Probe has a solid stainless steel tip and is the strongest of the three tip designs, similar to a sharpened pencil, and while not recommended for puncturing dura, customers who must do so may have better success with the S-Probe tip. The V-Probe has a tapered, conical-shaped tip for easier penetration and reduction of trauma upon entry, in addition this specialized tip permits the recording site to be closer to the tip of the probe.

How to I determine the specifications of a probe from the probe name on the case?

• Use the guide found here to identify the specifications of your probe.

What is the lead time for custom probes?

• 4-6 weeks

What is the reinforcement tube for?

• The reinforcement tube has two functions: 1) It reinforces or strengthens the junction between the thinner recording tube (where the electrode sites are) and the connector block, which is the interface to the recording headstage, and 2) it allows for a convenient connection point for the microdrive. Most probe users attach the microdrive to the reinforcement tube. The reinforcement tube is thicker in diameter than the recording tube, which allows for a strong connection point.

Where can the fluid capillaries be located?

• Fluid channels can be placed between any two sites in a S or U probe. Fluid channels on a V probe must be placed in the first half of the sites closest to the connector.

How should I sterilize my probe before use?

• We recommend ethylene oxide gas or UV sterilization. Alcohol is not a sterilant, but can be carefully used if EtOH or UV light is not available. However, the longer the probe – and specifically the tip – is exposed to alcohol the more likely the epoxy holding the wires in place will soften. While probes may be rinsed briefly with alcohol, they must be allowed to air dry immediately thereafter. The tips of the probe must not be allowed to sit in alcohol for more than 15 seconds as exposure to alcohol runs the risk of dissolving or damaging the epoxy which holds the electrode sites in place.

What is the inner and outer diameter of fluid channels on probes?

• The inner diameter is 40μm and the outer diameter is 60μm.

What is the expected impedance of the U- V-, and S-probes?

• Electrodes within Plexon u-, v-, and s-probes are not designed to be a specific impedance. The probes are specifically built for single-unit isolation, although we do not expect a specific impedance. The individual electrodes are typically 15um diameter wire.

Does Plexon have a recommendation for microdrives?

• Plexon has put together a list of microdrives as a reference. You can view this information here: https://plexon.com/recommended-microdrives/

Do you have any suggestions for reducing noise in a linear probe with a fluid channel?

• The fluid line connector/tubing should be shielded/grounded. The best way to avoid this is to wrap the drug tubing in aluminum foil and ground it.

 

Check out these Q&A documents from our linear probe webinar series. Many topics are discussed including optogenetic stimulation, probe implantation, dura penetration, and more.

Webinar 2

Webinar 3

Webinar 4

Webinar 5