Properties of our electrodes:
  • Excellent signal-to-noise ratio (SNR)
On average, our electrodes provide extracellular spike amplitudes around a few mV.
  • Perfectly straight electrodes
Our electrodes are straight (not curved or spiral) with enough rigidity to penetrate brain tissue without suffering any deviation.
This
guarantees precise stereotaxic positioning at deep brain structures.
  • Suitable for electrode arrays
The electrode sharpness and the smooth glass insulation surface minimises tissue dimpling.
  • Ideal mechanical and electrical properties
Pure tungsten has the high stiffness and excellent electrical properties.
The borosilicate glass insulation gives a uniform insulation of a very high resistivity and provides increased stiffness, especially at the tip.
  • Good replacement for glass micropipettes in extracellular recording
Metal-tip electrodes are stronger than glass micropipettes and can isolate extracellular single-unit activity for longer time periods and record larger amplitudes (Wolbarsht et al. 1960; Guld 1964).

Electrode specification:
Shank diameter:
Overall probe length:
Glass insulated length:
Overall probe diameter:
Taper:
Tip length (impedance):
Tip conditioning:
Termination option:
125µm tungsten wire (other diameters on request)
45±1mm, 76
±1mm, 100±1mm, 125±1mm (other lengths on request)
overall probe length minus 15mm (bare tungsten wire)
~200µm±15%
~5
deg for dura removed, ~15 deg for dura piercing tip electrode
see table below
unplated

no connector
pin 220-P02 (0.032"/0.81mm)
pin Harting 09 67 000 8576 (0.040"/1.04mm)
socket 220-S02 (0.032"/0.81mm)
other connectors on request
connectors add extra ~8mm to probe length
Tip length selection guide:
Electrodes with short tips, up to ~20µm, are designed for single unit spike recordings.

Electrodes with longer tips, above ~20µm, are intended for recordings of multi-unit activity (MUA) or local field potentials (LFP).


Selection of standard electrodes for dura removed experiments:
Tip length
[µm]
7.5
±1
10.0
±2.5
12.5
±2.5
15.0
±3
17.5
±3
20
±3
25
±3
30
±5
35
±5
40
±5
45
±5
50
±5
longer
on  request

Impedance
[MOhm]
mean  ±1std
5.5
±1.6
4.2
±1.3
3.3
±1.0
2.6
±0.8
2.2
±0.6
1.8
±0.5
1.3
±0.4
1.0
±0.3
0.8
±0.2
0.7
±0.2
0.6
±0.1
0.5
±0.1

Electrode impedances measured in 0.9% saline with 10nA current at 1kHz.
Due to the very fine and delicate nature of the microelectrode tip for dura removed experiments, it is strongly advisable to handle them with great care.


Selection of electrodes with strengthen tips for dura piercing experiments:
The same
as for dura removed experiments, however the electrodes for dura piercing experiments have approximately 30% lower impedances due to increased surface of wider tapered electrode tip compared to electrodes for dura removed experiments (see electrode construction).

Selection of electrodes with extra fine tips for very small cells and large fibers:
The same
as for dura removed experiments, however the electrodes with extra fine tips have approximately 30% higher impedances due to decreased surface of narrower tapered electrode tip compared to electrodes for dura removed experiments (see electrode construction).

Electrode construction:


If you are unsure which tip length would work best for your experiments, we would be pleased to discuss your requirements.
We can also prepare a selection of different electrode tip lengths in your first box at no extra cost.

Every electrode is inspected for highest quality assurance.

NL04 coupler





Flexible silicone insulated electrode extension cables:
- extension cable with socket 220-S02 matching pin 220-P02,
- extension cable with socket Harting 09 67 000 8476 matching pin Harting 09 67 000 8576.

Extension cables are available:
- in four colours (black, red, blue and yellow; other colours on request),
- in four lengths (40cm, 60cm, 80cm, 100cm; other lengths on request) and
- with 3 conductor sizes (22AWG and outer diameter 1.8mm, 24AWG OD 1.7mm, 26AWG OD 1.5mm).
All cables are £9 each.
Electrode extension cable






Straight cut lengths of tungsten wire:
-
diameter 0.127mm ±1% (0.005") , purity 99.95%+, temperature annealed, electropolished, condition clean, max bow <0.001''.
-
made from the highest quality Japan tungsten wire.

length
[mm
±1mm]
38
(1.5")
45 60

76
(3")
90

100
(4")
110

125
(5")
150
(6")
quantity [pcs] /
price [GBP]
  50 / £30
100 / £50
 500 / £250
1000 / £400
50 / £30
100 / £50
 500 / £250
1000 / £400
50 / £40
100 / £60
 500 / £300
1000 / £500
50 / £40
100 / £60
 500 / £300
1000 / £500
50 / £60
100 / £100
500 / £400
1000 / £700
50 / £60
100 / £100
500 / £400
1000 / £700
50 / £80
100 / £120
500 / £500
1000 / £850
50 / £80
100 / £120
500 / £500
1000 / £850
50 / £100
100 / £140
500 / £600
1000 / £1100
Typical lengths 1.5", 3", 4", 5", 6"  are available for next day delivery, other lenghs are manufactured on request with maximum lead time of 1 week.

Other diameters (0.1mm/0.004'', 0.15mm/0.006'', 0.2mm/0.008'', 0.25mm/0.01'', 0.50mm/0.02'') of straight cut lengths of tungsten wire are manufactured on request.



Microelectrodes Ltd., Cambridge, UK
Monday-Friday: 9am to 5pm (UK time)
office@microelectrodes.net
tel. +44 7503 311208