Hoefer SG500 - Manual (Page 6)

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p4
Pouring gradients from the top
Filling a container with a gradient (e.g. casting
acrylamide pore gradient gels) can be done either
dense solution first (“from the top”), or light
solution first (“from the bottom”).
To fill from the top:
1
Proceed as described in Section 1, putting light (final
or top) solution in the reservoir chamber (step 3) and
dense solution in the mixing chamber (step 5).
2
Place the delivery outlet against the upper edge of
the receiving container. Adjust the pump rate so that
the solution flows evenly down the side in a smooth,
continuous stream. The delivery speed should be slow
enough that the newly arriving solution does not mix
with the underlying solution.
Alternatively, using a rigid cannula at the end of the
delivery tubing, hold the tip of the cannula just above
the surface of the solution, raising it smoothly as the
container fills.