Could I apply 10-20 Voltage via two Tungsten electrodes

Dear Sir

As title.

I would like to apply 10-20 Voltage via two Tungsten electrodes to acute brain slice with another stimulator? Because from the manual of STG, the max vlotage is 8V. And the resistance between the Tungsten electrode is 7 MOhm. I am afraid that some damage to the MEA amplifier will occur during this stimulation.

Thanks for your answer.

Good day.

SunJ

Dear SunJ

I think there is a misunderstanding: In current output mode, the STG is able to hold a constant current output of up to +/- 0.8 mA at a maximum voltage of 150 V (guaranteed 120 V). The maximum output of 8 V refers to the constant voltage output mode.

A high voltage applied to stimulating electrodes will not harm the MEA amplifier.

Best regards, Christine (MCS)

Thanks for your response.

Actually, I would like to apply 10-20V in voltage output mode. It seems not possible.

And another question is that is it possible for 7 Mohm bipolar electrodes to output 10-100 µA by STG current mode?

Thanks again.

SunJ

The STG has a +U and a -U output for each of the up to 8 output channels. You have a maximum output voltage of 8 V if you connect +U (or -U) vs. ground, but if you connect +U vs. -U, the output amplitude is doubled, that is, you have a maximum output voltage of 16 V (see also page 58 of the STG 2000 User Manual). If you still need a higher voltage, you can also connect +U of one output channel to -U of another output channel. Then again the amplitude is doubled, that is, up to 32 V.

> And another question is that is it possible for 7 Mohm bipolar
> electrodes to output 10-100 µA by STG current mode?

Ohm's law applies in this case, that is Voltage U = Resistance R * Current I. In your example, U = 7000 000 Ohm * 0.000010 Ampere = 70 V. As the STG has a compliance voltage of approx. 150 V (120 V guaranteed), your current limit will be at about 20 µA with a 7 MOhm electrode. For 100 µA, you would need 700 V.

Best regards, Christine