Beckman Coulter COULTER LH 750 System, Справочник, Страница: 34 / 120

PN 4277248DD
3-2
OPERATION PRINCIPLES
AUTOMATIC ASPIRATION MODE
Effect of Reagents
The conductive diluent must affect cells minimally, if at all.
Both lytic reagents must destroy erythrocytes without significantly affecting leukocytes. They
must work rapidly to satisfy the speed with which the system works.
The leukocyte preservative must
r
Provide clear separation of the white blood cell populations, and
r
Preserve leukocytes in their near-natural state for accurate cytometric measurement.
Reticulocyte Analysis
A supravital dye, New Methylene Blue, is incubated with whole-blood samples. The dye
precipitates the basophilic RNA network found in reticulocytes. Hemoglobin and unbound
stain are removed by adding a clearing reagent, leaving clear spherical mature RBCs and
darkly stained reticulocytes.
Stained reticulocytes are differentiated from mature red cells and other cell populations by
light scatter, direct current measurements, and opacity characteristics.
3.2 AUTOMATIC ASPIRATION MODE
The system automatically transports, mixes, aspirates and processes specimens.
Loading Specimens
1. The operator places specimen tubes, which can be identified by bar-code labels, into
cassettes. Each cassette and the tube positions in the cassette are identified by bar-code
labels.
2. You can load up to 12 standard or Hemogard cassettes with 144 samples into the loading
bay at one time. Figure 3.2 shows the loading bay filled with cassettes.
Transporting Cassettes
The system transports each cassette from the loading bay to the sampling station.
1. The right lift platform (Figure 3.2) rises beneath the stacked cassettes in the loading bay.
2. The bottom cassette is deposited on the platform.
3. The platform lowers the cassette to the level of the rocker bed.