How to test the MEA before coating and cell culture

We have bought the standard MEAs(200/30,6*6,TiN,Si3N4,i.R.).
Here are two questions:
Q1:

We want to test the MEA before cell culture to have a general view of the signals when blank load. So how should i set up the system?

As a try, we fill the bath with D-water or PBS, and then connect the probes of the multimeter with two contact pads on MEA, one of which is led from the reference. It is a general way when testing many electro-equipments, but this time we got a quite strange result: the electrodes between the two contact pads behave like a diode, that means we got about 8M OHm impedance firstly, and when i exchanged the probes, we got infinite impedance.

Is the way we test it wrong?

To test this, is the amplifier you provide a must?
Can a self-made one replace it?

Q2:
Beside the two ways you mentioned in the user manual,Is there a third way to activate the hydrophilicity?

Thank you

Dear Fang Chen,

we usually recommend to use our MEA amplifier to test the MEA chips. With a properly pretreated / hydrophilized surface and good 30um diameter electrodes you should observe a noise level of 5-10uV.
The use of PBS, HBSS or any other stnadard Medium for this purpose is fine (NOT distilled water). Please connect El. 15 to ground on MEAs with internal reference.

Hydrophilization is best to be done by Plasma Cleaning or incubation with a high protein solution (eg. FCS). As an Alternative coating with Cellulose nitrate in MetOH might improve the surface (but is less efficient than the two other ways)

Thomas

>>We have bought the standard MEAs(200/30,6*6,TiN,Si3N4,i.R.). >Here are two questions: >Q1: >>We want to test the MEA before cell culture to have a >general view of the signals when blank load. So how should i >set up the system? >>As a try, we fill the bath with D-water or PBS, and then >connect the probes of the multimeter with two contact pads >on MEA, one of which is led from the reference. It is a >general way when testing many electro-equipments, but this >time we got a quite strange result: the electrodes between >the two contact pads behave like a diode, that means we got >about 8M OHm impedance firstly, and when i exchanged the >probes, we got infinite impedance. >>Is the way we test it wrong? >>To test this, is the amplifier you provide a must? >Can a self-made one replace it? >>Q2: >Beside the two ways you mentioned in the user manual,Is >there a third way to activate the hydrophilicity? >>Thank you </

>>We have bought the standard MEAs(200/30,6*6,TiN,Si3N4,i.R.). >Here are two questions: >Q1: >>We want to test the MEA before cell culture to have a >general view of the signals when blank load. So how should i >set up the system? >>As a try, we fill the bath with D-water or PBS, and then >connect the probes of the multimeter with two contact pads >on MEA, one of which is led from the reference. It is a >general way when testing many electro-equipments, but this >time we got a quite strange result: the electrodes between >the two contact pads behave like a diode, that means we got >about 8M OHm impedance firstly, and when i exchanged the >probes, we got infinite impedance. >>Is the way we test it wrong? >>To test this, is the amplifier you provide a must? >Can a self-made one replace it? >>Q2: >Beside the two ways you mentioned in the user manual,Is >there a third way to activate the hydrophilicity? >>Thank you </
tadam