Expression of CD antigens on Raji and MEC2 cells treated with purine analogs (1 M, 24 hours) analyzed using flow cytometry. (a) Raji + CdA, (b) Raji + FdA, and (c) MEC2 + CdA. Raji and MEC2 cells were exposed to CdA or FdA (1 M, 24 hours), incubated with FITC- or PE-conjugated antibodies against CD antigens, and analyzed by flow cytometry. The grey area represents untreated cells; the black outline is cells exposed to a purine analog. The figures are representative of 3 technical replicates. A shift in the median fluorescence intensity indicates up- or down-regulation of an antigen. Differential abundances of these CD antigens are quantified in Table 1.