Bio-Rad Criterion™ XT Tris-Acetate Precast Gels User Manual
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Section 7
Troubleshooting
Improper storage of Criterion XT gels can produce numerous artifacts. Criterion XT Bis-Tris gels should be
stored flat at ambient temperature. Criterion XT Tris-acetate gels should be stored flat at 4°C. Avoid freezing. If
you suspect your gels have been stored improperly, DO NOT USE THEM.
Problem
Possible Cause
Solution
Samples do not migrate into gel
Tape at the bottom of the cassette
Remove tape
not removed
Insufficient buffer in integral buffer chamber
Fill integral buffer chamber with 60 ml
running buffer
Insufficient lower electrode buffer
Fill both halves of the lower buffer tank with
400 ml running buffer when running two gels
Electrical disconnection
Check electrodes and connections
Bands “smile” across gel, band pattern
Excess heating of gel
Check buffer composition
curves upward at both sides of the gel
Completely fill both halves of the lower buffer
tank with 400 ml running buffer when running
two gels
Do not exceed recommended running
conditions
Skewed or distorted bands, lateral
Excess salt in samples
Remove salts from sample by dialysis or
band spreading
desalting column prior to sample
preparation
Insufficient sample buffer
Check buffer composition and dilution
or wrong formulation
instructions
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