BIO RAD VERSADOC User Manual page 54

Problem
Fluorescent image has
high background
Filter wheel does not
turn
Epi lamps are not turning
on
Integration time to
acquire image has
increased
Poor
chemiluminescence
sensitivity
Possible Cause
Image was taken without being
removed from glass plate
660 NM filter is not in place
Wrong application selected
Light leak
High fluorescence agarose
used
Auto-fluorescence from sample
Destain (if appropriate) was
insufficient
Obstruction in filter wheel
housing
Custom lens is causing
obstruction
Bad filter wheel cable or
connection
Poorly seated lamps
Bad lamps
Door interlock not working
Lamp intensity has decreased
with age
Incorrect f-stop setting
Incorrect application selected
Sample may have degraded
Incorrect lens/filter used
Sample on platen with chemi
tray installed
Incorrect f-stop setting
The 660IR cutoff filter was not
removed from the lens
Insufficient integration time
User's Manual • 6-
Solution
Remove plate from sample.
Thin polyacrylamide samples
can be transferred to exposed
x-ray film and imaged using
UV-epi mode
Install 660 NM filter onto lens
Verify / reselect correct
application
Check for light leaks, ensure
Camera Module tightly
connected to
Use low fluorescence agarose
Remove sample and acquire a
control image
Increase destain
Check for and remove
obstruction
Contact Bio-Rad for
assistance
Reconnect / replace cable
Turn the lamps in the sockets
to make sure lamps are
seated properly in their
sockets
Replace lamps
Contact Bio-Rad
Replace lamps
Open aperture and reacquire
the image
Verify application is correct for
sample
Some Chemi samples have a
short lifetime, make sure the
sample is hot and fresh
Use the 50 mm high NA lens
for best chemi results and use
no filter Position 5 or higher
Place sample on chemi tray or
remove tray from sample
chamber
Adjust f-stop to a lower value,
f/1.4 recommended.
Remove 660 cutoff filter
Integrate sample for a longer
time
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