A quality assurance program (QAP) is conducted twice yearly to ensure proficiency and provide training for member laboratories in PBMC fractionation and cryopreservation from research blood specimens. Blood specimens from a single HIV-pos and HIV-neg donor are transported to member laboratories for simultaneous processing the following day according to procedures in the IVRN Lab Manual IVRN_Lab_Manual_Updated_April_2013.pdf  A fresh locally-sourced healthy donor specimen is also processed at each site.Cryopreserved cells are returned to the central assessment laboratory, thawed, counted and assessed for immunological function. A laboratory is certified as proficient in specimen processing if at least one returned specimen conforms to all quality standards: fractionation and post-thaw recovery, viability, and immune function, as discussed in the QAPreport  IVRN_23rd_QAP_Report.pdf; IVRN_25th_QAP_Report.pdf; IVRN_26th_QAP_Report.pdf  If a laboratory fails a QA round, the QAP coordinator will investigate the cause of the failed result, and provide remote or on-site training if required. Failure in two consecutive QA rounds will disqualify a laboratory from participating in new studies until proficiency is restored, thereby ensuring that valuable trial and cohort blood specimens are entrusted to laboratories with currently certified expertise.