Summary of practices that did not conform to the recommended protocol distributed to all participating labsa

Procedure identified as being in conflict with the QAP protocolPresence of procedure in laboratory
Short Ficoll spin (<20 min)X
Inclusion of platelet deposit on tube adjacent to PBMC layerXXXXX
Non-cell culture-grade DMSO usedX
Insufficient medium used for cell washing stepsX
Inclusion of all white cells as the PBMC countXXXXXX
DMSO too concentrated (>10%)X
Freezing medium at ambient temperature when added to PBMCX
Ampoules not prechilledXXX
PBMC kept in freezing medium too long before being frozenX
PBMC not stored at cryogenic temperatures (i.e., stored at >−150°C)X
  • a These practices were identified during telephone interview sessions. Each of these practices could have potentially reduced PBMC quality.