CD4 and AIDS: Calcein-labeled CD4 T cells and autologous CD8 T cells procured from the PBMC of AIDS patients were co-incubated and observed directly by fluorescent microscopy: similar to the in-situ PCR results (Table 2), 7.0 ± 0.65 % of the CD4 T cells were conjugated by CD8 T cells compared to 0.9 ± 0.07% of the cells of the matched healthy controls.