Bio-Rad Model 491 Prep Cell and Mini Prep Cell - Manual (Page 32)

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a. High salt concentration in the
sample.
a. Sample overloaded.
b. Incorrect %T.
c. Incorrect gel length or gel tube
size.
d. Inadequate cooling.
a. Proteins too dilute and UV
detect ion not sufficient.
b. Insufficient protein load.
c. %T too high and proteins remain
in gel or diffuse to un detectable
level.
d. %T too low, protein mi grates
with ion front.
a. O-ring or dialysis membrane in
elu- tion chamber missing or
damaged.
a. Mechanical stress.
b. It is normal for a gel to pull
slightly away from the wall.
c. Polymerization too fast.
d. Heat of polymerization not
dissi pated.
a. Buffer concentration or pH are
in correct.
a. Remove salts by dialysis,
desalting column, etc.
a. Decrease sample load.
b. Refer to section 4.
c. Check Table 2.
d. Cooling flow rate should be 100
ml/min.
a. Use silver stained SDS-PAGE gels
to analyze indi vidual prep cell
frac tions.
b. Increase total protein loaded.
c. Decrease %T. See detailed
optimization procedure, section
4.2.
d. Increase %T. See detailed
optimization procedure in
Section 4.
a. Check to see if O-ring and dialysis
membrane are in place and not
dam aged.
a. Reduce handling of the gel during
polymerization.
b. Refractive phenomena often
accen tuate the appear ance of
these regions. They will not affect
protein resolu tion.
c. Check catalyst concentra tion.
d. Cool gel during polymer ization.
a. Make fresh buffer.
1. Sample requires a long
time to en ter the gel.
2. Poor resolution.
3. No detectable proteins
in collected fractions.
4. Elution buffer floods
down into lower buffer
chamber.
5. Air pockets between gel
and gel tube.
6. Running conditions
outside recom mended
range.
Problem Cause Solution
Section 6
Troubleshooting Guide
27