Air bubbles – run prime
cycle
The time for the liquid meniscus to pass from the
lower to the upper detector is unreasonably short.
Run a “Prime cycle”, before
re-analyzing the sample.
Air bubbles – run prime
cycle
Air bubbles were detected by the start detector in
the measuring tubes.
Possible orifice blockage:
Run prime cycle and then
re-analyze
The liquid meniscus in the measuring tube never
passed the lower detector.
Possible orifice blockage:
Run prime cycle and then
re-analyze
The liquid meniscus in the measuring tube passed
the lower detector but never passed the upper one.
WBC Differential Abnormalities (LYM, MID, GRAN)
WBC DIFF: High
interference between
populations.
The calculated populations for LYM, MID, GRAN
overlap too much. Often in pathological samples
with granulocytosis or lymphocytosis a blood
smear is recommended.
Blood sample too old or
pathological sample. Follow
laboratory’s protocol for
verification of results.
WBC DIFF: No WBC
population found; slide
review advised.
There was no mode in the WBC distribution
between the LYM-L and GRAN-H settings.
WBC DIFF: Only one
WBC population found;
slide review advised.
There was only one mode in the WBC distribution
between the LYM-L and GRAN-H settings. Often
in pathological samples with granulocytosis or
lymphocytosis a blood smear is recommended.
WBC DIFF: Too many
WBC population found;
slide review advised.
There were more than two modes in the WBC
distribution between the LYM-L and GRAN-H
settings.
9.3 Parameter Limitations of Automated Blood Cell Counters
This section describes the different factors that may interfere with HCT, HGB, MCV,
MPV, PLT, RBC, RDW, WBC and WBC differential determination.
Turbidity, in the blood sample, due to any number of physiological and/or therapeutic factors may produce falsely
elevated HGB results. The instrument however, is compensated throughout the linear range of the instrument.
Increased turbidity may be seen in cases where the red blood cells are resistant to lysing.
This condition will cause a falsely elevated HGB result but can be detected by monitoring
the MCHC.
Extremely elevated WBC may produce falsely elevated HGB results due to turbidity. In case
of extreme WBC counts, the following is recommended: The diluted sample should be
centrifuged and the supernatant fluid checked on a spectrophotometer for turbidity.
Lipemia,
hyperproteinemia
and
hyperbilirubinemia
Elevated lipids in the blood sample will give the plasma a “milky” appearance which may
disturb the spectrophotometric measurement of HGB. Similar problems may occur with
hyperproteinemia (high protein concentration) and hyperbilirubinemia (high bilirubin
concentration). Accurate HGB determination can be achieved by using reference methods
and a plasma blank.
The mixing of fetal and maternal bloods may produce a falsely elevated HGB value.
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