PD-1/PD-L1-IN-31

Cytotoxicity assays are usually based on the assessment of cell membrane damage, which can also be indirectly detected by measuring cell viability. Detection methods include MTT assay, CKK-8 assay, LDH assay and ATP assay, etc.

PBMC thawing for immune assays recovers viable cryopreserved peripheral blood mononuclear cells for downstream functional or phenotypic readouts, including ELISPOT, intracellular cytokine staining, proliferation assays, and flow-cytometric immunophenotyping. Cryopreserved PBMCs can support immune monitoring because antigen-specific T-cell function and major CD4/CD8 phenotypes may be retained after optimized freezing and thawing, although some lymphocyte subsets and activation or memory markers can be altered by cryopreservation. The technical objective is rapid warming of the frozen vial followed by controlled dilution and removal of DMSO-containing cryomedium, because thawing and wash conditions measurably affect viable PBMC recovery and downstream assay performance. Viability alone is insufficient for protocol evaluation because high viability may occur with low live-cell recovery, so both viable percentage and absolute live-cell recovery should be measured after thawing.