Multichannel Systems Roboocyte2 Manual - Manual (Page 73)

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7 Recording with Roboocyte2 Control Software
7.1 Preparations for Recording
General Preparations
Either you plan to do recordings in manual mode or automated mode, there are some
preparations common to both.
Installing the Measuring Head
Important: The glass electrodes have to be backfilled with the electrolyte without any air bubbles.
Otherwise, the electrode resistance will be too high. The Ag/AgCl electrodes have to be placed
into the electrolyte, but keep the blank silver part of the electrode outside the electrolyte to
minimize slow voltage drifts over time. Blank silver does not generate a stable junction potential.
1. Take a fresh measuring head out of the box; be careful not to touch the tips of the glass
electrodes.
2. Insert a fine pipette tip (micro loader, for example) into the glass electrode as deeply as possible
(without breaking the delicate electrode tip) and carefully fill about two thirds of the volume of
the glass electrodes with the electrolyte solution (so that the only Cl-coated part of the Ag/AgCl
electrode can be inserted into the electrolyte), slowly withdrawing the pipette tip during the
process. MCS recommends to use either 3 M KCl solution or a mixture with 1.5 M KAc, 1 M KCl.
The latter has the advantage of a less pronounced tendency to form salt crystals.
3. Wait a short moment until the tip has been completely filled. Check this by using a microscope,
if necessary.
4. There should be no air bubbles in the glass capillaries. Otherwise the electrode resistance will
be too high. Gently tap on the glass to remove any air bubbles if necessary.
5. Take two of the chlorided silver wires out of the box (stored in the small plastic bag) and insert
them into the glass capillaries. Be careful and avoid that the coating of the wires is scraped away.
Residues of the coating material could possibly clog the capillaries.