Hoefer SUB Series - Manual (Page 26)

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p18
Using The Horizontal Gel
Electrophoresis Units
Preparation of Agarose Gels
The amount of agarose needed to give a particular
% gel needs to be calculated; for example a 0.8%
gel can be made by dissolving 0.8 grams of agarose
powder in 100 mls of running buffer. The type of
running buffer used should always be the same for
the gel as that used in the buffer tank. The agarose
needs to be fully dissolved before the gel can properly
form. This can be achieved by heating with swirling
in a water bath or incubator set to 70 °C or by heating
on a magnetic heating block with a magnetic stirring
bar inserted. The flask should always be covered
to prevent evaporation of the buffer and a higher
concentration gel resulting. These methods may take
longer than 1 hour for the agarose to fully dissolve.
Alternatively, the agarose can be dissolved in about
5 –10 minutes using a microwave oven. The agarose
solution should be covered and the microwave set to
low. The agarose dissolves better if the microwave is
periodically stopped and the solution swirled. Before
pouring, the agarose solution should be checked for
undissolved agarose crystals which can affect the
mobility characteristics of gels. If these are present,
agarose dissolving should be continued. The agarose
solution should be cooled to 50 – 60 °C before
pouring. If poured at too hot a temperature, the gel
will be more likely to leak and also the comb may
become distorted.