Principles Of The Procedure; Hemoglobin Concentration - Siemens ADVIA 2120 Operator's Manual

Principles of the Procedure

WBC Count
The whole blood sample is mixed with ADVIA 120 BASO reagent that contains
acid and surfactant. The red cells are hemolyzed, and the white blood cells are
then analyzed using 2 angle laser light scatter signals.
Bibliography
Cremins J and Orlik J: Leukocyte differential method. US Patent 5,518,928
(1996)
RBC / Platelet Count
Both red blood cells and platelets are analyzed by a single optical cytometer after
appropriate dilution of the blood sample with ADVIA 120 RBC/PLT reagent.
The red blood cells are isovolumetrically sphered and lightly fixed with
glutaraldehyde to preserve the spherical shape. Red cells and platelets are
counted from the signals from a common detector with 2 different gain settings.
On the ADVIA 2120/2120i Hematology system the platelet signals are amplified
considerably more than the RBC signals. Coincidence correction is made to each
of the counts so that accurate counts are made over a wide range of each cell
type.
Bibliography
Kim YR and Ornstein L: Isovolumetric sphering of erythrocytes for more
accurate and precise cell volume measurement by flow cytometry. Cytometry
3(b):419-427 (1983)
Zelmanovic, et al: US Patent pending
RBC / Platelet Size
The method of sizing red cells and platelets uses the simultaneous measurement
of laser light scattered at 2 different angular intervals, which eliminates the
adverse effect of variation in cellular hemoglobin concentration on the
determination of cell volume.
Bibliography
Kerker M: The Scattering of Light and Other Electromagnetic Radiation.
Academic, New York, NY, Chapter 3 (1969)
Groner W and Tycko DH: Characterizing blood cells by biophysical
measurements in flow. Blood Cells 6:141-157 (1980)

Hemoglobin Concentration

The hemoglobin method is a modification of the manual cyanmethemoglobin
method developed by the International Committee for Standardization in
Hematology (ICSH).
Bibliography
ICSH Recommendations for Reference Method for Hemoglobinometry in
Human Blood, ICSH Standard EP 6/2 (1977)
9-22 Regulatory Information