Bio-Rad PROTEAN® IEF Cell Accessories - Manual (Page 41)

10.2.3. IPG Strip Storage
IPG strips can be stored indefinitely at -80 °C after the run. A rehydration tray and lid
can be used to store the IPG strips.
10.2.4. IPG Strip Equilibration (prior to 2 nd dimension)
To equilibrate IPG strips, fill each channel with DTT Equilibration buffer and soak for 10
minutes. Discard the solution and add the iodoacetamide equilibration solution and soak
for an additional 10 minutes. Then place the IPG Strip on the second dimension gel.
Section 11
Troubleshooting
If a system or operator error occurs the appropriate error message will appear on the LCD
display. The power is not applied to the system/electrodes when an error message is displayed.
Problem Cause Solution
Initial low or zero • Poor contact between IPG • Check contact between IPG
current strips and electrode. strips and electrode. Make
sure the focusing tray lid is
placed correctly.
• Incomplete contact between • Check placement of focusing
tray electrodes and PROTEAN tray to insure proper contact
IEF Cell connections.
between tray electrodes and
PROTEAN IEF Cell connec-
tions.
• Incomplete IPG strip • Make sure that the IPG strips
rehydration are completely and evenly re-
hydrated. Check rehydration
volumes and rehydration times.
Voltage is not • Salt concentration too high • Check salt concentration
increasing during and/or desalt sample.
voltage ramping steps.
Voltage does not • Bio-Lyte concentration too • Reduce Bio-Lyte concentration
reach programmed high to 0.2% (v/v).
value, or maximum • Set voltage too high for IPG • Program volt-hours for
voltage is reached strip size and pH gradient. focusing step to insure
very slowly complete focusing of sample.
• Excess sample during re- • If greater than recommended
hydration did not enter gel, sample volumes are used make
or IPG gels overswelled sure all off sample has entered
with excess sample gel, or remove excess sample
prior to focusing.
Large fluctuations in • IPG strips contain poorly • Check rehydration volume
Voltage and current. rehydrated regions, or and time. Make sure rehy-
(also resistance error IPG strips have dried out dration solution is evenly
message displayed) during the run. distributed during rehydration.
• Current limit too high. • We recommend a current limit
of 50 µA/strip. Make sure the
correct number of IPG strips
was entered.
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