Beckman Coulter COULTER ACT 5diff User Manual

PN 177196BB
7-10
DATA MANAGEMENT AND REVIEW
DATA ANALYSIS - MEASUREMENT PRINCIPLES
b. The WBC/BASO bath aperture sensor system determines the cell count and size of
WBCs. The WBC Lyse specific lytic action on the WBCs in this bath allows the
system to further differentiate, by size, the basophils from the rest of the WBCs.
3. To sense particles using the Coulter Principle, a current flow is established through an
aperture so that changes in that flow can be monitored.
a. In this sensing system, an electrode is placed on each side of a calibrated aperture.
1) The most visible electrode (referred to as counting head) is the conductive
metallic housing attached to the front of the RBC and WBC/BASO baths.
2) The second electrode (referred to as the bath electrode) is not as conspicuous;
this electrode is located inside the bath.
3) The aperture is located between the counting head and the bath electrode.
a) An 80 µm aperture is used in the WBC/BASO bath.
b) A 50 µm aperture is used in the RBC bath.
b. When the count circuit is activated and an electronically conductive reagent is in
the bath, an electric current continuously passes through the aperture.
c. When cells are suspended in the conductive reagent and the cells are pulled through
the aperture, the electrical resistance between the two electrodes increases.
d. The count syringe supplies a constant low vacuum to the RBC bath and the
WBC/BASO bath to pull the diluted sample through the aperture.
4. The resistance created by a cell in the aperture generates an electrical pulse.
a. The pulse is sensed and counted as a particle.
b. The amplitude (height) of the pulse (the amount of resistance) is directly related to
the size of the particle that produced it.
5. Generated pulses have a very low voltage which an amplification circuit increases so that
the electronic system can better analyze the pulses and eliminate the background noise.
Aperture Sensor System
Solution to be analyzed
Electrodes
Analyzing
electronic
circuit
Vacuum
constant
Time
Pulse
V
olts
7650331A
Current
constant
7196002B
Aperture
Counting head
(external electrode)
Bath electrode
(internal electrode)

Beckman Coulter COULTER ACT 5diff Specifications

General

Brand	Beckman Coulter
Model	COULTER ACT 5diff
Category	Laboratory Equipment
Language	English