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and CD14-PE. The mean values of the recovery and purity as well as the range for the different procedures are
given in the following tables:
Without washing
Without concomitant fixation
With concomitant fixation
Recovery
Purity
Recovery
Purity
96.4
92.3
96.6
91.6
95 / 97.5
90.1 / 94.3
95.4 / 98.1
90.1 / 92.6
With washing
Without concomitant fixation
With concomitant fixation
Recovery
Purity
Recovery
Purity
95.6
94.0
96.2
97.2
95 / 97.3
90.3 / 97.3
95.4 / 97.5
92.7 / 99.4
INTRA-LABORATORY REPRODUCIBILITY
On the same day and on the same cytometer, 31 measurements of the percentage of CD3+ lymphocytes were
carried out on the same sample (whole blood from a healthy donor). The lysis procedure used was concomitant
fixation in the absence of washing. The results obtained are summarized in the following table:
Whole blood
Number
Mean (%)
SD
CV (%)
CD3+
Lymphocytes
31
60.72
1.61
2.7
LIMITATIONS
1. Flow cytometry may produce false results if the cytometer has not been aligned perfectly, if fluorescence leaks
have not been correctly compensated for and if the regions have not been carefully positioned.
2. Accurate and reproducible results will be obtained as long as the procedures used are in accordance with the
technical insert leaflet and compatible with good laboratory practices.
3. In the case of a hyperleucocytosis, dilute the blood in PBS so as to obtain a value of approximately 5 x 10
9
leucocytes/L (7).
4. In the case of a polyglobulinaemia, dilute the specimen in PBS so as to obtain 5 x 10
12
10).
5. VersaLyse must be brought to room temperature (18 – 25°C) before use.
6. Verify the preparations using the naked eye to assess the efficacy of lysis. If they are cloudy or if the light
diffraction histograms are unusual, lysis may be incomplete.
7. The erythroblasts may be incompletely lysed and appear on a light diffraction histogram in the same location
as the leucocytes (11).
8. Acetazolamide, an inhibitor of carbonic anhydrase can completely inhibit the action of VersaLyse (12).
9. In certain disease states, such as severe renal failure or haemoglobinopathies, lysis of red cells may be slow,
incomplete or even impossible. In this case, it is recommended to isolate mononucleated cells using a density
gradient (Ficoll, for example) prior to staining (13).
TRADEMARKS
Beckman Coulter, the stylized logo, and the Beckman Coulter product and service marks mentioned herein are
trademarks or registered trademarks of Beckman Coulter, Inc. in the United States and other countries.
Symbols Key
Glossary of Symbols is available at beckman.com/techdocs (document number B60062)