Help please

I have some trouble in doing caradic acute slice in MEA.
I want to ask the following quessions.Could you help me?
1)In article"Impulse propagation in late-stage embryonic and neonatal murine ventricular slices" written by Professor Hescheler.They said that "the slices were placed onto the electrode area and covered with a small volume of Iscove's medium,just sufficient to prevent to prevent desiccation.After having attached to the MEA surface,futher medium was added" I don't know how to attach slice to the MEA surface ,because it will float in fluid.
2)I want to get conduction velocity but some singals we could get appear at the same time.I don't know why?Should I advance an external stimulation electrode on to the tissue by means of a manual micromanipulator?
Thanks.

I visited the Lab of Prof Hescheler some time ago and discussed this issue with one of the scientists. They add a really small volume of medium after placing the slice on the MEA (about 50-100uL). Than the volume is gradually increased in several steps. This procedure is very similar to the procedure described for brainslices.

Do you pretreat the MEA surface? (PEI, Fibronectin, Laminin...?)

Please also see our reply to your support request by e-mail.

Greetings

Thomas