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CyFlow
™
Space | Operating Manual | March 2021
ii) Electrode-Principle: Determination of V
The method for True Volumetric Absolute Counting supported by the CyFlow™ Space is
based on the precise measurement of a fixed sample volume by means of two electrodes.
During analysis by the CyFlow™ Space, the sample liquid loses contact first from the upper
and then from the lower electrode. These events trigger a START and a STOP signal,
respectively which is stored by software.
Figure 4: True Volumetric Absolute Counting by the Electrode Principle
The volume
V
of sample liquid analysed between the START and STOP signal is physically
defined by the distance of the two electrodes and the diameter of the sample tube. The
analysed volume is exactly 200 µl (= counting volume).
Effects of the sample meniscus in the tube are eliminated because the START and STOP
electrodes are arranged symmetrically. The sample conductivity does not influence the
volumetric measurement, as long as the fluids can be detected electrically.
6.3
Precision and Reproducibility
Precision and reproducibility of the Sysmex Partec instruments can be demonstrated and
checked with
Count Check beads (low, medium, high)
(REF 05-4010).
6.4
Benefits of True Volumetric Absolute Counting
Sysmex Partec instruments can perform traditional Dual- and Single-Platform counting and
unique True Volumetric Absolute Counting, the latter offering unique benefits:
i) Precision
A high precision of better than 5% is guaranteed by precise counting and mechanical
volume measurement. The counting reproducibility is better than 2% rel. standard deviation.
Summary of Contents for CyFlow Space
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