Trypsin abolishes maturation inducing effect of tumor lysate. Lysate from HCT-116 colorectal tumor cells which have been harvested by using 0.02% EDTA was were divided, one part was exposed to trypsin (0.25%) and the other part was sham treated with PBS for 5 min. In order to inactivate trypsin, 100% human AB serum (2× higher volume) was added to both arms after 5 minutes. DCs were stimulated for 3 days with trypsin-exposed or sham-treated tumor lysate and examined for expression of surface maturation markers CD40 and CD86.
Herzog et al. BMC Research Notes 2011 4:153 doi:10.1186/1756-0500-4-153