FIG. 6.

Analysis of apoptosis in T-lymphocyte populations prepared from PBMC. CD4⁺ and CD8⁺ lymphocytes were prepared from PBMC of mock-infected and infected calves as described in Materials and Methods. Ethanol-fixed lymphocytes were stained with Telford reagent. The PI fluorescence of individual cells with hypodiploid DNA content was measured with a flow cytometer.