Depletion efficacy and readout time. The presented experiment (Exp III) is representative for a set of 3 mismatched experiments performed under these conditions. (A,D) Alloreactivity of responder cells, the untreated control and the photodepleted product determined in 6-day mixed lymphocyte reactions against the original stimulator (ExLy) or third-party PBMCs 1 and 4 days after the photodepletion procedure. (B,C,E,F) Alloreactive courses of responder cells, the untreated control, and the photodepleted product determined in 4- to 6-day mixed lymphocyte reactions against the original stimulator (ExLy) or third-party PBMCs 1 and 4 days after the photodepletion procedure. Stim indicates irradiated stimulator cells; Resp, unmanipulated responder PBMCs; 3rdP, pooled third-party PBMCs; UC, untreated control; ExLy, expanded lymphocytes; PD/_5.0TH and PD/_7.5TH, PD products generated using 5.0 and 7.5 μM TH9402, respectively; cpm, counts per minute; and pd, after depletion.