Temperature effect on the baseline noise in MEA measurements

It is a well known fact that increasing temperature increases noise in all kind of electronics, which applies also to cell and tissue measurements by microelectrode arrays (MEAs). We show that ambient temperature may have a surprisingly big role in the noise level of MEA measurements. To study that we measured the baseline noise when the MEA amplifier was subject to temperature variations, either in a temperature chamber or by preventing amplifier unit's normal heat exchange. Around room temperature (+24 degrees C) the RMS value of the baseline noise was found to increase approximately 0.14 mu V/degrees C, which is a huge variation as the default RMS noise at that temperature with our setup was only around 5.5 mu V. Additional cooling of the MEA amplifier could thus be a clever way to decrease the noise level at very sensitive measurements and on the other hand, one should not interfere the amplifier's normal heat exchange to the ambient air in order to avoid additional warming and thus increasing the noise level.