Siemens ADVIA 2120 Operator's Manual page 387

During the second step, ADVIA 120 PEROX 2 reagent and ADVIA 120 PEROX
3 reagent are added to the peroxidase reaction chamber. The 4-chloro-1-naphthol
in ADVIA 120 PEROX 2 reagent and the hydrogen peroxide in ADVIA 120
PEROX 3 reagent stain the sites of peroxidase activity in the granules of
neutrophils, eosinophils, and monocytes. Lymphocytes, basophils, and large
unstained cells contain no granules with peroxidase enzyme activity.
A constant volume of the cell suspension from the Perox reaction chamber passes
through the flowcell. The two fluids flow as independent, concentric streams (no
mixing), with the ADVIA 120 PEROX SHEATH stream encasing the sample
stream. The absorbance and the forward light-scattering signatures of each blood
cell are measured. The optical signals are converted to electrical pulses by
photodiodes. After processing, the information is displayed in two histograms.
The Perox Y histogram contains the forward-scattering data (cell size). The
Perox X histogram contains the absorption data (peroxidase staining). The two
histograms are combined to form the Perox cytogram from which cells are
identified and counted.
Bibliography
Cremins J, et al: Method for the determination of differential white blood cell
count. US Patent 4,801,549
Ansley H and Ornstein L: Enzyme histochemistry and differential white cells on
the Technicon Hemalog D. In: Advances in Automated Analysis, Technicon
International Congress 1970, Volume 1. Therman Associates, Miami, FL, p 437
(1971)
Saunders AM: Hemalog D system - recent development. In: Advances in
Automated Analysis, Technicon International Congress 1972, Volume 3. Mediad
Inc., Tarrytown, NY, pp 27-32 (1973)
Groner W, et al: Peroxidase activity of human monocytes as a function of pH and
fixation observed with the Hemalog D. Presented at ACHE II (2nd workshop of
the Automated Cytochemistry and Hematology Exchange), Marlow-on-Thames,
England, May 22-23 (1980)
Basophil / Lobularity Method
The Basophil/Lobularity method was developed by Cremins and Orlik to provide
both accurate basophil counts and a measure of cellular lobularity.
This method provides precise, accurate, and rapid recognition of basophils.
Cremins and Orlik discovered that basophils are particularly resistant to lysis by
a combination of acid and surfactant.
When the EDTA anticoagulated whole blood sample is mixed with ADVIA 120
BASO reagent, the red blood cells are hemolyzed and the cytoplasm is stripped
from all white cells except basophils. The sample is then analyzed by two-angle
laser light scattering detection using a laser diode. The white cells are classified
into three categories: basophils, mononuclear (MN) cells, and
polymorphonuclear (PMN) cells.
9-46 Regulatory Information