Preliminary Report: Evaluation of Storage Conditions and Cryococktails during Peripheral Blood Mononuclear Cell Cryopreservation

The use of cryopreserved peripheral blood mononuclear cells (PBMCs) has proven critical in both clinical and biomedical applications. While utilized, in numerous settings, the functionality of frozen PBMCs is often limited, and a disconnect exists between measured viability and outcome. In this study we investigated parameters affecting outcome including storage protocol, freeze media, and assessment assay. PBMCs were isolated from seven healthy donors and cryopreserved in: (1) a media-based cocktail (SAIC), (2) CryoStor 7.5 (CS7.5), and (3) CryoStor 7.5 plus caspase inhibitors (CS7.5 ± Inh). All samples were stored in vapor phase liquid nitrogen (static) with replicates exposed to a thermal cycling regime, which mimicked typical sample handling (cycle). Viability was assessed immediately postthaw by trypan blue. Cryopreservation-induced delayed-onset cell death (CIDOCD) was evaluated postthaw using the Vybrant® Apoptosis Assay (VAA) that differentiated viability, apoptosis, and necrosis by fluorescent mi...