Multichannel Systems MEA Manual - Manual (Page 61)

Troubleshooting
61
The next screen shot shows the effect of shielding: The noise level is neglectible, and the baseline is
steady. The shielding has been achieved with a metal plate connected to the metal part of the 68-pin MCS
high grade cable connector and placed above the amplifier. You could also use aluminum foil or a Faraday
cage for the same effect, for example.
9.5 Missing Spikes or Strange Signal Behavior
MEAs wear out after multiple uses or over a longer time of use, for example, for long-term cultures.
The insulation layer gets thin over time. This is considered a normal behavior.
Possible causes:
? The insulation layer is too thin. As a result, the MEA gets the behavior of a low pass filter. This means,
that the signal frequency may be shifted to a lower frequency, and spikes are missing.
 Optically control the MEA with a microscope. If concentric colored rings (Newton rings) are visible
(due to light interference), the insulation layer is too thin and you should use a fresh MEA.
? The insulation layer has been abraded and is missing in parts. This will result in a short circuit between
the electrodes or tracks and the bath. You will still see signals, but as an unspecific smear over the
complete array.
 Use a fresh MEA.