BD FACSymphony A5 SE - High event rate

High event rate
Possible causes Recommended solutions
Air bubbles in the sheath filter or
flow cell
Remove the air bubbles. See Removing air bubbles (page 27).
Threshold level is too low Increase the threshold level. See the BDFACSDiva™ Software Reference Manual
for instructions.
PMT voltage for the threshold
parameter is set too high
Set the PMT voltage lower for the threshold parameter. See the BDFACSDiva™
Software Reference Manual for instructions.
Sample is too concentrated Dilute the sample.
Sample flow rate is set to HIGH Set the sample flow rate to MED or LOW.
Low event rate
Possible causes Recommended solutions
Threshold level is too high Lower the threshold level. See the BDFACSDiva™ Software Reference Manual for
instructions.
Air bubble or debris in the flow cell Prime the fluidics system. See Preparing the fluidics (page 31).
PMT voltage for the threshold
parameter is set too low
Set the PMT voltage higher for the threshold parameter. See the BDFACSDiva™
Software Reference Manual for instructions.
Sample is not adequately mixed Mix the sample to suspend the cells.
Sample is too diluted Concentrate the sample. If the flow rate setting is not critical to the application,
set the flow rate switch to MED or HIGH.
Sample injection tube is clogged Remove the sample tube to allow backflushing.
If the event rate is still erratic, clean the sample injection tube. See Cleaning the
fluidics (page 37).
Erratic event rate
Possible causes Recommended solutions
Sample tube is cracked Replace the sample tube.
Air bubble or debris in the flow
cell
Prime the fluidics system. See Preparing the fluidics (page 31).
Bal seal is worn Replace the Bal seal. See Changing the Bal seal (page 42).
Sample injection tube is
clogged
Remove the sample tube to allow backflushing.
If the event rate is still erratic, clean the sample injection tube. See Cleaning the fluidics
(page 37).
Contaminated sample Prepare the specimen again. Ensure that the tube is clean.
Sheath filter is dirty Replace the filter. See Changing the sheath filter (page 41).
Chapter 9 Troubleshooting 107