Hoefer TE22 - Manual (Page 13)

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p5
Prepare two lengths of 9 mm (3/8") vinyl or silicone
tubing. Slide hose clamps (4 total) onto each end of
two lengths of tubing. Attach one end of each length
of tubing to a heat exchanger port. Attach the free
ends of each length of tubing to the circulator bath
ports; one to the inlet and the other to the outlet.
Secure the connections with the hose clamps.
3
Place ( do not drop) a magnetic stirring bar in the
buffer tank. (Dropping objects into the tank may crack
the alumina plate.) Set the unit onto a magnetic
stirrer and fill transfer buffer to the “Start fill level”
line on the front of the tank. (This requires approxi-
mately 0.7 liters.)
4
Set the stirrer to low-medium, which accomplishes
buffer circulation without forcing buffer through
the cassettes.
Assemble the transfer cassette
1
Pre-wet nitrocellulose or nylon membranes with
distilled water. Pre-wet PVDF or other hydrophobic
membranes in methanol. Then soak all membrane
types in transfer buffer for 2–5 minutes.
2
Open the cassette by releasing both latch tabs along
the edge opposite the hinges. Place the opened
cassette into a tray filled with at least 3 cm of trans-
fer buffer.
3
Assemble the transfer stack so that molecules will
migrate toward the membrane. For negatively charged
macromolecules (such as nucleic acids and most
proteins), build the stack on the grey half of the
cassette (and then later position the lid so that the
grey side faces the red lead, or anode (+).
Place one 3 mm-thick foam sponge on the opened
submersed cassette and press gently until all air is
expelled. Place one sheet of blotting paper on the
Note: Always wear gloves when
handling membranes to avoid
getting fingerprints on them.
Important! Take great care in
removing all air bubbles at each
step because the presence of
air bubbles, especially between
the membrane and gel, blocks
transfer.
Note: Even if no cooling is
required for your system, the
buffer should be circulated with a
stirrer to avoid buffer depletion at
the electrodes.