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CELL-DYN
®
3200 System Operator’s Manual
9140181H—October 2001
Quality Control
Quality Control Guide
Section 11
Establishing the X-B WBC Target Value
The Target Values for X-B WBC can be established in the same way as the Target
Values for the RBC indices.
Each laboratory should establish its own target value for the X-B WBC parameters.
It is suggested that the process be started by using the default (preset) values
displayed in the following table. The action limits in the table may be used or
widened during the study. Reenter the default action limits shown in the following
table when the Target Values are confirmed. The values for the action limits may
be widened depending on the specimen population analyzed by the laboratory. The
values for the Lower/Upper Acceptance Limits may also be used or widened
depending on the specimen population analyzed by the laboratory.
Collect data from 20 batches of 20 specimens each for a total of 400 specimens.
Data collection should be from specimens which represent the typical specimen
population that is processed through the instrument. When all 20 batches are
complete, print the X-B DATA DISPLAY screen for WBC. Calculate the mean,
standard deviation (SD), and coefficient of variation (CV) for each parameter. The
CV for LYM 0°, LYM 10°, NEU 0°, and NEU 10° should be <2.5%. The CV for
NEU 90°, NEU 90° depolarized, and NEU-EOS should be <5%. If the CV for each
index meets these criteria, enter the calculated mean value as the target value and
set the action limits to 5% for LYM 0°, LYM 10°, NEU 0°, and NEU 10°, and to 10%
for NEU 90°, NEU 90° depolarized, and NEU-EOS.
NOTE:
Laboratories analyzing specialized patient populations (as described
above) may need to widen the action limits slightly to accommodate
results from these abnormal patients.
If the CV for each index is more than the limits described above, evaluate another
400 specimens and repeat the calculations.
When an acceptable target value has been entered, evaluate data from an additional
400 specimens to confirm the entered values.
Default (Preset) X-B WBC Values
Parameter
Acceptance Limits Target Value Action Limit
LYM 0°
20–100
64
20%
LYM 10°
20–130
72
20%
NEU 0°
100–210
158
20%
NEU 10°
90–210
171
20%
NEU 90°
40–160
121
20%
NEU 90 DEP° 0–70
21
20%
NEU-EOS°
0–40
22
30%
Interpreting X-B WBC Results
A suggested protocol and guidelines for interpreting X-B data can be found in
Chapter 1 of
Laboratory Hematology, An Account of Laboratory Techniques
,
edited by I. Chanarin.
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