Abbott CELL-DYN 3200 System Operator's Manual page 104

Principles of Operation
Flow Cytometry
WBC Measurement
Overview
1 Focused Laser Beam
2 0° Scatter
3 10° Scatter
4 90° Scatter
5 90°D Scatter
Figure 3.3 WBC Light Scatter
3-10
The Optical Channel is used for the determination of WBC data. During sample
aspiration, 20 µL of sample is segmented in the Shear Valve for WBC
measurement. The WBC Syringe dispenses 0.973 mL of WBC lyse to the Shear
Valve. The sample and lyse are then transferred to the WBC Mixing Chamber
where the dilution is swirl mixed, resulting in a 1:50 dilution ratio.
The Sample Transfer Pump transfers the WBC dilution from the mixing chamber
to the sample feed nozzle in the Optical Flow Cell. At the same time, sheath
reagent, under constant pressure in the Sheath Reservoir, is transferred to the sheath
feed nozzle in the Optical Flow Cell and injected into the cell. At the same time,
the Sample Metering Syringe injects 46.5 µL of the WBC dilution into a sheath
stream. The sample stream is then hydrodynamically focused to align the cells in
single file as they pass through the Optical Flow Cell, which is an optically clear
quartz chamber. A vertically polarized Helium Neon Laser is the light source.
The instrument measures:
• Both types of forward angle light scatter (1° to 3°, referred to as 0°, and 7° to
11°, referred to as 10° or narrow angle)
• Both types of orthogonal (side) light scatter (70° to 110°, referred to as 90°,
and 70° to 110° depolarized, referred to as 90°D).
This is referred to as MAPSS™ (for Multi-Angle Polarized Scatter Separation)
technology. Various combinations of these four measurements are used to classify
the WBC subpopulations and provide morphological flagging.
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CELL-DYN ® 3200 System Operator's Manual
9140181H—October 2001
Section 3