Troubleshooting – Hoefer SE615 User Manual
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p18
Troubleshooting
symptom
possible cause
recommended action
1. Gels adhere to glass plates
Dirt, grease or
Soak plates in a strong laboratory detergent;
when opening sandwich.
fingerprints on plates.
rinse well in distilled water. Handle with
gloves only.
2. Gels cast simultaneously
Different amounts of
Use the same amount of overlay on all
are different sizes.
overlay were used on
separation gels. Add the overlay as rapidly
the separation gels
as possible.
before polymerization.
3. Caster leaks.
Gasket leaks.
Apply a light film of Gel Seal to the gasket
each time the unit is used.
Gasket damaged.
Check the foam gasket for nicks or wear and
replace if necessary.
Stack too tall.
Remove filler plates or gel sandwiches until
the stack top is just below the level of the
caster wall.
4. Gel heights uneven.
Bubbles trapped
Pour the monomer solution into one sandwich
under gel sandwiches.
and allow the groove in the plug to evenly
distribute the solution.
Polymerized gel
Make sure the groove in the triangular plug is
in groove.
clean and clear of material.
Insufficient time for
Wait one minute before overlaying the gels.
gel levels to stabilize.
Add the same amount of overlay to each
sandwich.
5. Sample wells damaged
Air bubbles under
Remove air pockets before inserting combs.
or leak.
comb teeth.
Slide comb into solution at an angle. If comb
must be removed, add more monomer
solution before reinserting the comb.
Insufficient
Allow the gel to set for a minimum of 1 hour.
polymerization.
Comb removed
Slowly remove the comb at a slight angle to
too abruptly.
prevent damaging the gel.
Poor polymerization.
Degas stacking gel solution.
Increase catalysts up to 0.1% v/v TEMED,
0.1% v/v APS.
6. Gel sandwiches
No wax paper
Place wax paper between sandwiches
difficult to separate.
between glass plates.
in the stack.
7. Uneven gradient gels.
Uneven layering.
Add sucrose or glycerol to the heavy
monomer solution. Add a small amount of
bromophenol blue to the heavy solution to
track gradient formation.
Decrease the pump rate.