3 casting troubleshooting: agarose gels – Bio-Rad Model 111 Mini IEF Cell User Manual
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Problem
Cause
Solution
b. Polymerization time
b.
Optimize polymerization time
is too long, causing
by placing excess solution in
gel to dry onto plastic
a 12 x 75 mm glass test tube
at the edges of the plate.
and putting the test tube under
Especially true with gels
the polymerization light.
polymerized with APS.
Remove plate 15 minutes
after test tube solution gels.
c. Incorrect procedure used
c.
Do not slide plate sideways
to lift plate from casting
before removing it. Do not
tray.
pry the plate up with fingers.
Twist the spatula to raise the
plate edge nearest the
spacer. This allows air to
penetrate between the gel
and the plastic without
forming a vacuum.
d. Dirty glass plates and
d.
Wash plates and casting tray
casting tray.
with Bio-Rad’s Cleaning
Concentrate, and rinse them
thoroughly with deionized or
distilled water.
e. Use of wrong side of gel
e.
Gels must be cast on the
support film.
treated (hydrophilic) side of
gel support film.
f. Use of Bio-Lyte 8/10
f.
Adhesion is decreased when
ampholyte.
using ampholytes with a pH
≥
8.0. Increase ammonium
persulfate to 0.7 mg/ml (7 µl
of 10% APS stock per ml
solution) and TEMED at
1 µl/ml.
g. Gel support film exposed
g.
Always keep gel support film
to light for extended
sealed in its light-proof
periods.
package. Store at room
temperature.
7.3 Casting Troubleshooting: Agarose Gels
Problem
Cause
Solution
1.
Gel does not adhere to
a. Use of incorrect side of
a
Always cast gels on treated
gel support film; sticks to
gel support film.
(hydrophilic) surface of gel
casting tray.
support film.
b. Dirty glass plates and
b.
Wash plates and casting tray
casting tray.
with Bio-Rad’s Cleaning
Concentrate, then rinse
thoroughly with deionized or
distilled water.
c. Casting tray not
c. Allow 15-30 minutes for
equilibrated to 55 °C.
casting tray to equilibrate to
55 °C in oven.
d. Agarose solution too hot
d.
For maximum adhesion, cast
or too cold.
agarose solutions at 55 °C.
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