Siemens ADVIA 2120, Operator'S Manual, Page: 275 / 477

8-6 Methods
BASO Cytogram: Cluster Analysis
The BASO cytogram is divided into 50 counting channels on each axis.
When the high-angle light scatter (nuclear configuration) is plotted on the x axis,
and the low-angle light scatter (cell size) is plotted on the y axis, distinct
populations or clusters are formed.
Cluster analysis identifies each population based on its position, area, and
density, and then counts the number of cells/nuclei in each population.
The following BASO cytograms were obtained from a representative patient
specimen.
1 Noise
2 Blast cell nuclei
3 Mononuclear WBCs
(Monocyte and Lymphocyte nuclei)
4 Basophils
5 Baso Suspect
6 Saturation
7 Polymorphonuclear WBCs
(Neutrophil and Eosinophil nuclei)
Noise Area
This area contains platelets, RBC stroma, and other cellular debris that are not
included in the total white blood cell count (WBCB).
Blast Cluster
When present, blasts appear in the blast cluster.
Mononuclear Cluster
In normal samples, the MN population contains lymphocyte and monocyte
nuclei.
Basophil Cluster
With their cytoplasm intact, basophils are much larger than the white cell nuclei
and appear in the Basophil cluster.
Baso Suspect Cluster
Contains unlysed cells other than basophils. Counts from this area are not
included in the basophil count.
Saturation Area
Typically, this area contains air bubbles that are not included in the basophil or
WBCB count.