Siemens ADVIA 2120, Operator'S Manual, Page: 10 / 477

1-6 Welcome to the ADVIA 2120/2120i Hematology System
2
Baso Reaction Chamber
3
RBC Reaction Chamber
6
Shear Valve
7
Reagent Pump Assembly
Shear valve
The shear valve ( 1 ) is made up of two ceramic disks.
The rear disk ( 2 ) is stationary. The front disk ( 3 ) rotates
to “shear” or divide the sample into appropriate aliquots
for analysis.
The front disk also rotates to allow aspiration for direct
cytometry.
(side view of the UFC)
1
3
2
Reaction chambers
The reaction chambers are machined pockets
in the
UFC
assembly where the sample and
reagents are mixed and the cytochemical
reaction takes place.
There are five reaction chambers.
1 Hgb Reaction Chamber
(Not Visible)
2
Baso Reaction Chamber
3
RBC Reaction Chamber
4 Retic Reaction Chamber
5
Perox Reaction Chamber
1
2
3
4
5
The perox reaction chamber ( 5 ) is temperature controlled. The mixture of sample
and three reagents, PEROX 1, PEROX 2, and PEROX 3, is heated to achieve the
desired cytochemical reaction.