Haematology analyzer:
BLOOD COUNTER Coulter HmX & LH 500:

Principle:
A suspension of blood cell is passed thru a small orifice simultaneously with an electric current. The individual cells passing thru the orifice introduce an impedance change in the orifice determined by the size of the cell. The system counts the individual cells and provides cell size distribution.



*Hemoglobinometry:-
The lytic reagent used for the CBC parameters the blood so the system can count Leukocytes and sense the amount of haemoglobin. The lytic reagent rapidly and simultaneously destroys the erythrocytes and converts a substantial proportion of the haemoglobin to a stable pigment while it leaves leukocytes nuclei intact. The absorbance of the pigment is directly proportional to the HGB concentration of the sample.









*Differential measurements:
The coulter establish WBC differential technology using three measurements: (individual cell volume, high-frequent conductivity and laser-light scatter).

- Volume analysis:
Using low-frequency current has been used since 1967AD. It has been evaluated s possible adjunct to differential WBC.




- Conductivity analysis:-
Cell walls act as conductors to light-frequency current, as the current passes through the cell walls and through each cell interior, it detects differences in the insulating properties of cell components. The current characterizes the nuclear and granular constituents and chemical composition of the cell interior.



- Light scatter analysis:
In the instrument, monochromatic laser light using forward angle scatter analyzes the internal structure, granularity and surface characteristics of WBC as each cell pass through the flow cell.



Components:
• Main unit:
The main unit includes:
- Sample handler.
- Diluter.
- Analyzer
- Electronic power supply.
- Pneumatic power supply
• Data Management System (DMS).
• Printers
• Reagents:-

1) Diluent (isoton):
- Dilutes the whole blood samples
- Stabilizes cell membranes for accurate counting and sizing.
- Conduct aperture current
- Carries and focuses the sample steam in the flow cell
- Rinses the system between samples.

2) Lytic reagent:-
- Rapidly lyses RBCs, freeing HGB. and reducing the size of cellular debris to level that does not interfere with WBC count.
- Causes a substantial conversion of the HGB to a stable pigment, the absorbance of this pigment is directly proportional to the HGB concentration.




3) Diff. PAK:-
Use for differential measurement, contains PAK LYSE & PAK RESERVE.
A- PAK LYSE:-
- Dilutes the blood samples.
- Rapidly lyses RBCs.
- Reduce cellular debris to an insignificance level.
B- PAK RESERVE:-
- Preserve WBCs in near-native state.

4) Retic. Prep. Reagent kit:-
Include tow reagents, using for preparing sample for reticulocytes analysis.
• Reagent A:
Reagent A is specially formulated, New Methylene Blue dye that stains the reticulum.
• Reagent B:
Clearing reagent that remove HGB from the cell without removing the precipitated stain RNA complex; keeping the cell and its membranes intact.

5) Cleaning agent:
Cleans and rinses the internal surface of the Diluter components.