Xl mcl flow cytometer

CD4 lymphocyte count (CD3+CD4+) was determined by whole-blood 4-color direct immunofluorescence using a XL-MCL flow cytometer (Beckman/Coulter, Miami, FL). In order to convert the % of total lymphocyte values generated by the flow cytometer to absolute count for each subset, the total lymphocyte count was determined using a MaxM electronic hematology analyzer (Beckman/Coulter, Miami, FL). Serum viral load was measured by determining the number of HIV-1 virions per milliliter (ml) of peripheral blood plasma using the Cobas Amplicor HIV-1 Monitor RT/PCR assay (version 1.5, Roche Molecular Systems, Branchburg, NJ). The lower limit of sensitivity of this assay was 400 copies of HIV-1 RNA/ml of plasma. Flow cytometry for CD4 was completed the same day and an aliquot of plasma was frozen and stored at −70°C for viral load assay, which was batched and run weekly.

CD4 lymphocyte count (CD3+CD4+) was determined via whole-blood four-color direct immunofluorescence using an XL-MCL flow cytometer (Beckman/Coulter, Miami, FL). The total lymphocyte count was determined using a MaxM electronic hematology analyzer (Beckman/Coulter). CD4 count at baseline and 24 months were both tested in the model.