Specifications

MEA-System Manual

3.4.1 Microelectrode Arrays (MEAs)

The recording field of a standard MEA is a square grid of 8x8 electrodes with a total length

between 120 μm to 5 mm, in the middle of a circular (about 2 cm wide) recording / culture

chamber.

The layout of the MEA electrodes follows the scheme of a standard grid: The first digit is the

column number, and the second digit is the row number. For example, electrode 23 is positioned

in the third row of the second column. The numbering follows the standard order from left to

right, and from top to bottom. This numbering is used in the documentation of the MEAs, the

MEA1060 amplifiers, and in MC_Rack. That means, if you want to record data from electrode 23,

you choose channel 23 for setting up the channel layout map in MC_Rack. Please make sure that

the appropriate 2-dimensional data source setup 2 dim. (MEA) for a MEA60-System and MEA120-

System has been selected in MC_Rack. For more details, please refer to the MC_Rack Help or

Manual.

Microelectrode arrays are available in various configurations:

 Different electrode layouts (8x8, 6x10, High Dense 2x(5x6), 4 Quadrants, Hexa)

 Different electrode diameters and spatial resolutions

 Different electrode materials (Titanium nitride, gold, platinum)

 Opaque (titanium) or transparent (indium tin oxid) tracks

For more information on MEA types, electrode layouts, MEA handling, coating and cleaning,

please refer to the MEA Manual.

3.4.2 Signal Amplification and Filters

The standard MEA amplifier combines the probe interface with a band pass filter and the signal

amplification in one instrument.

The MEA1060-BC amplifier with blanking circuit is a 60-channel preamplifier with a broad

bandwidth. Filter specifications and gain are defined by the following filter amplifier.

Different filter settings are used to enhance the signal-to-noise ratio. The pass band of the filter

amplifier depends on the signal type. It is generally useful to filter the data with a cutoff at the

highest signal frequency.

For slow signals like field potentials, a bandwidth of 1 to 300 Hz is appropriate. If you like to

record fast signals like spikes, a pass band of 300 Hz to 3 kHz is suitable. Cardiac signals have fast

and slow components; therefore, you usually need a wider bandwidth of 1 Hz to 3 kHz.

Multi Channel Systems provides custom amplifiers with a bandwidth of your choice, from 0.1 Hz to

10 kHz. Please note that it is often wise to acquire the data with a broadband amplifier and use

the digital filter of the free MC_Rack program to change the pass band and filter the raw data.

This way, you are much more flexible in designing your experiments. As a further advantage, you

can see the original (not filtered) data as well. This is especially important because all filters are

known to distort signals. On the other hand, you may need a higher sampling rate to avoid

aliasing, and the signal-to-noise ratio is lower. See also the chapter "Data Acquisition" for more

information.

The standard gain of a MEA amplifier is 1200, which is fine for most applications, but MCS can

also provide amplifiers with a gain of your choice (from 100 to 5000) as well. For large signals (for

example, from heart preparations), you need a lower gain to prevent a saturation of the

amplifier. Please note that the gain is a fixed hardware property; and that you cannot change the

gain of the amplifier by software controls.