Bio-Rad DCode™ Universal Mutation Detection System - Manual (Page 80)

9.1 Equipment (continued)
Problem Cause Solution
Perpendicular gradient (DGGE only)
Glass plate cracked Excessive force at Apply only one turn
comb gasket to thumb gasket screw
after it touches glass
Gel solution leaks during casting Not sufficient pressure Make sure pressure
on comb gasket clamp screws are
turned two turns
Poor contact between Reassemble glass
comb gasket and plates as in Section
spacers 4.1. Visually confirm
contact at spacers and
comb gasket
Casting stand gasket Position gray gasket
positioned incorrectly so that it covers the entire
bottom section of the
glass plate
Wrong comb gasket Make sure correct
comb gasket is used
Misaligned comb gasket Insure that comb gasket
notches are against
spacer notches
Misaligned plates Pressure clamp may
force plates to shift if
sandwich clamps are not
tight. Insure that
sandwich clamps are
tightened
Misalignment of spacers Check alignment at
and glass plates bottom of glass plates,
using alignment slot on
casting stand
Damaged or dirty Replace spacers or
spacers and/or combs combs
Different thickness of Use spacers and comb
spacers and comb of same thickness
Dirty inlet fitting Replace fitting
or missing O-ring
Loose stopcock Tighten stopcock/inlet
port screw connection
No air vent plug Plug vent after casting gel
Damaged or non- Replace with Bio-Rad
Bio-Rad glass plates glass plates only
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