Comparison of TrypLE™ Select animal-free tyrpsin immobilization and cold PBS with cell scraping for harvesting mature HOCl-oxidized lysate-loaded DCs. (A) DCs were matured with LPS and IFN-γ for 16 h following lysate-loading. It was observed that mature lysate-loaded DCs that were harvested using TrypLE™ Select animal-free tyrpsin replacement exhibited approximately 30-40% reduction in the levels of MHC Class I (P = 0.13; NS) and HLA-DR (P = 0.15; NS) compared to DCs that were harvested with cold DPBS and cell scraping. Data were the mean of 3 independent experiments (i.e. DCs from 3 different individuals) ± SEM in research-scale Nunclon™Δ Surface T25 cm2 flasks. P values were determined with unpaired Student's t test. NS indicated that P values were not significant. (B) Mature lysate-loaded DCs that were harvested with TrypLE™ Select animal-free tyrpsin replacement were as efficient as DCs that were harvested with cold DPBS and cell scraping in presenting MHC Class I-restricted HER-2/neu and MART-1 peptides and stimulating HER-2/neu and MART-1 CD8+ T cells in intracellular IFN-γ assessments.