Evaluation of monoclonal antibody reagents from three different manufacturers using flow cytometric two-color immunophenotyping

We evaluated a flow cytometric (FCM) two-color immunophenotyping of CD3+/CD 4+ T-helper and CD3+/CD8+ T-suppressor lymphocytes in whole blood samples f rom HIV-infected individuals using monoclonal antibody reagents from three different manufacturers. Lymphocytes were firstly determined using CD45/CD1 4 in association with a forward scatter/side scatter gating strategy. CD3+/ CD4+ and CD3+/CD8+ were then determined and compared. Reagents from all man ufacturers showed good separation of lymphocytes, monocytes and granulocyte s with high purity and recovery. There was a good correlation of the percen tage of CD3+/CD4+ and CD3+/CD8+ lymphocytes amongst each of the manufacture r's reagents, but the fluorescent intensities of positive cells were not th e same. This difference can result in poor discrimination of positive and n egative non CD3 cells leading to erroneous results.