The lack of terminal cell death in vivo may be alternatively explained by the rapid clearance of dead cells by macrophages, thus we used the fluorogenic caspase-3 substrate PhiPhiLux to purify OVA-specific CD8+ T-cells at day 5 of infection into active caspase-3hi and caspase-3low fractions (Fig. 5A). Here, CD8A is linked to infection.