Plexon V-Probe

Introducing the new V-Probe* multi-site, linear electrode. The V-Probe takes the best of the very popular U-Probe to the next level, while also leveraging the benefits of the redesigned, conical-shaped tip to further minimize trauma to the brain tissue upon insertion. It is exceptionally durable, highly customizable, and often used in acute research with medium to large animals.

The V-Probe is a multi-use, multi-site, linear electrode with recording sites positioned on the side of a sharpened, symmetric cone. Compared with our very popular U-Probe, the cone-shaped tip is believed to result in less trauma to the brain tissue upon penetration by minimally displacing tissue along the track. The new design also permits an electrode site to be placed closer to the tip of the probe.

V-Probes are made in a single-row configuration, with a choice of 8, 16, 24 or 32 channels, in lengths up to 150mm.

The platinum/iridium electrode recording sites are available in 15, 20, 25 and 40µm diameter options. The small electrode site diameter (15µm) enables effective single-unit recording, while a unique etching process of the electrode surface results in lowered impedances without significantly changing the overall surface area of the exposed recording site. The result is a small site suitable for resolving single units coupled with low impedance for a better single-to-noise ratio.

V-Probes also come with the flexibility of integrating up to four fluid channels or optical fibers at specified locations – sites 1-4 illustrated in the 8 channel configuration below. Please see the Technical Spec tab for more information on correct placement.

Like U-Probes, V-Probes are exceptionally robust due in part to their hand-crafted, stainless steel construction (as opposed to silicon), and ability to penetrate deep within the brain. When used according to proper procedures, V-Probes will support many uses over a long period of time. Reusing the exact V-Probe from experiment to experiment is not only economical, but more importantly removes one element of potential variability.

You may also wish to explore other options in Plexon’s family of Specialty Probes, Electrodes and Arrays including our Thumbtack Probe for chronic application with medium to large animals.

The illustration below depicts the anatomy of a standard V-Probe by front and top (connector) view. The 8 channel, single electrode configuration is featured as the example (see page 7 of the V-Probe Technical Guide located in the Resources tab for more details on this particular channel count). Electrode sites are numbered accordingly (sites 1 – 8 from connector to tip).

V-Probes are rather customizable, as outlined in the table below. It is possible that V-Probes may be made outside of the specifications indicated. As such, it is recommended that you discuss your needs with a Plexon Sales Engineer to determine if your unique request may be accommodated.

Feature Specifications and Options Remarks
Application In vivo; acute
Channel counts 8, 16 24, or 32
Total probe length 30 to 150mm Length is customizable within range provided; however, the most typical request is 100mm. Total probe length is measured from tip to the connector. The difference between the total probe length and the reinforcement tube length is a minimum of 25mm.
Probe OD 185 to 360μm Probe diameters vary based on the number of electrodes, fluid channels and optic fibers. See the Probe diameter tables found in the Probe Technical Guide under Technical Specifications.
Reinforcement tube length 5 to 125mm Length is customizable within range provided
Reinforcement tube outer diameters 460 or 640μm Probe diameters of 236μm and greater require a 640μm reinforcement tube
Electrode construction 15μm Pt/Ir electrode site diameter, circuar shape, HML insulated (polyimide), and secured in medical-grade epoxy 15μm diameter sites are recommended for resolving single units (action potentials).
Electrode configurations Single
Inter-electrode spacing 50μm, 75μm, 100μm, 150μm, or 200μm along length of probe
Distance from tip to the closest electrode site
Dependant on probe diameter:
185 probe diameter: 320μm; 210 probe diameter: 360μm; 236 probe diameter: 410μm
260 probe diameter: 450μm; 300 probe diameter: 520μm; 320 probe diameter: 560μm
360 probe diameter: 620μm
The numbering of the electrode sites is such that channel #1 is closest to the connector. Conversely, the electrode site closest to the tip is the largest channel # on the probe.
Stimulation options Single: Up to four fluid capillaries and/or optic fibers Single: Able to accomodate up to four fluid capillaries/optic fibers. Must be placed within the half of sites closest to the connector. Examples: four fluid capillaries; or four optic fibers; or one fluid capillary with three optic fibers. The total count of fluid capillaries plus optic fibers may not exceed four.
Fluid capillary ID 40μm Fluid capillaries are slightly offset from the center line of the electrodes.
Fluid capillary OD 60μm
Optic fiber OD 50μm Optic fibers are slightly offset from the center line of the electrodes.
Connector interfaces
8 channel: CON/8o50m-10P
16 channel: 2x CON/8o50m-10P, CON/16m-V or CON/16o25m-18P
24 channel: 3x CON/8o50 or CON/32m-V
32 channel: CON/32m-V
All are Omnetics connectors.
Lifespan Robust and reusable with a minimum of thirty penetrations, likely many more

The V-Probe diameter table below provides the minimum diameters for all electrode, fluid capillary and optic fiber combinations.

Single Electrode Configuration:

Channels Fluid Capillaries or Optic Fibers Minimum Probe Diameter (μm) ^ Minimum distance from tip to 1st electrode (μm) Reinforcement tube diameter (μm)^
8 0, 1 185 300 460 or 640
8 2 210 300 460 or 640
8 3 260 300 640
8 4 300 300 640
16 0 185 300 460 or 640
16 1 210 300 460 or 640
16 2 236 300 640
16 3 300 300 640
16 4 320 300 640
24 0 210 300 460 or 640
24 1 236 300 640
24 2 300 300 640
24 3 320 300 640
24 4 360 300 640
32 0 260 300 640
32 1 260 300 640
32 2 300 300 640
32 3 320 300 640
32 4 360 300 640

*V-Probes are manufactured by Neuronelektród.

^Batch variation in wire inner diameter may require a larger probe diameter or larger reinforcement tube.

Guides and How To Papers

Technical Specs and Data Sheets