Bio-Rad Mini-PROTEAN® TGX™ Precast Gels for 2-D Electrophoresis - Manual (Page 35)

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Troubleshooting
12
Problem Cause Solution
Current is zero or less than
expected, and samples do not
migrate into gel Tape at bottom of cassette not removed Remove tape
Insufficient buffer in inner buffer
chamber Fill buffer chamber with running buffer
Insufficient buffer in outer buffer
chamber Fill inner and outer chambers to ensure
wells of the gels are completely covered
Incorrect cassette orientation Ensure shorter plate is facing gasket
Electrical disconnection Check electrodes and connections
Gels run faster than expected Running buffer too concentrated or
incorrect Check buffer composition
Gel temperature too high Do not exceed recommended running
conditions
Gels run more slowly than expected Companion running module left in tank
when running only 1–2 gels Remove companion running module
Buffer leaking from inner chamber Incomplete gasket seal Wet gasket with running buffer before use
Improper assembly of the gel into the
electrode/companion module Top edge of short plate should fit under
notch at top of gasket
Top of short plate should touch green
gasket
Bands “smile” across gel: band
pattern curves upward at both
sides of gel Excessive heating of gel Check buffer composition
Do not exceed recommended running
conditions
Insufficient buffer Fill inner and outer chambers to ensure
wells of gels are completely covered
Bands “smile” or “frown” within gel
lanes Protein load too high Load less protein
Sample or buffer preparation issues Minimize salts, detergents, and solvents
in sample preparation and sample loading
buffers
Incorrect running conditions Set correct voltage
Table 12 .1 . Troubleshooting electrophoresis and detection with Mini-PROTEAN ® gels . For more troubleshooting tips,
refer to the relevant instrument instruction manuals or contact Technical Support.