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CELL-DYN
®
3200 System Operator’s Manual
9140181K—July 2002
Principles of Operation
Flow Cytometry
Section 3
Resistant RBC
When a specimen containing resistant RBCs is run in the routine patient mode, the
lytic agent in the WBC lyse reagent may be insufficient to lyse the “resistant” cells
in the time allotted for the WBC count. Consequently, unlysed RBCs can be
erroneously included in the WBC count resulting in a falsely elevated value. When
this occurs, a significant amount of stroma will be present in the N1 region below
the WBC dynamic threshold on the 0º/10º scatterplot.
When these type of specimens are rerun in the Resistant RBC mode, the diluted
WBC sample is held in the mixing chamber 15 seconds longer than in the routine
patient mode. This additional lysing time is used to break down (lyse) the resistant
RBC cells and prevent them from interfering with the WBC count and differential.
NOTE:
A higher incidence of false positive band flags may be evident on
specimens run under the Resistant RBC specimen type.
