Beckman Coulter CytoFLEX Series Instructions For Use Manual page 283

Table 9.1 Troubleshooting (Continued)
Problem
The calculation of the
automatic compensation
experiment is incorrect.
The sample is flowing,
but no signal appears in
the plot.
B49006AH
Probable Cause
• Erroneous data acquisition.
• The gate is not set on the
appropriate population.
• The events of the acquired
cells are too low.
• The mean fluorescence of
the positive cells is too weak.
• The signal is outside of the
display range.
• The parent gate is not
positioned properly and does
not contain events.
• The population color setting
is too light.
• The threshold is too high.
Troubleshooting Table
Corrective Action
1. Ensure that the corresponding negative
control tube and the individual positive
tube acquired are from the same sample
type.
2. Ensure that the single colors collected
correspond to the correct tube name.
3. Ensure that the gate in the FSC/SSC plot
encloses the correct sample population.
4. Ensure that the positive gate in each
tube is correctly placed.
5. Modify the events to record to ensure
that enough events are collected for the
data population.
6. Select samples with a stronger positive
signal as the positive control.
Or
Use dedicated compensation beads such
as VersaComp Antibody Capture Beads
1. Use either
or to modify the
display range.
Or
Right-click the plot and select Property.
The Plot Property window appears. Select
Fit with sample.
2. Ensure that the parent gate is gated
correctly.
3. Change the display color.
4. Move the sample above the threshold
using one of the following methods:
• Decrease the threshold setting. Refer
to Adjusting the Threshold
CHAPTER 5, Data Acquisition and
Sample Analysis.
• Increase the gain setting. Refer to
Adjusting the Gain in
Data Acquisition and Sample
Analysis
Troubleshooting 9
in
CHAPTER 5,
9-17