Abstract
The calorimetric assay used 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) was compared with the 3H-thymidine incorporation assay in swine lymphocyte blastogenesis induced by phytohemagglutinin-P (PHA) and concanavalin A (ConA). The correlation coefficients were 0.70 (n=18, p<0.01) in PHA and 0.82 (n=18, p<0.01) in ConA. The maximal responses were observed in cultures of 2.0×106 cells/ml with the final concentration of 2.5-10.0 μg/ml in PHA or 2.5-5.0 μg/ml in ConA for 72 hr. The stimulation index of peripheral blood lymphocytes from clinically healthy pigs aged 6 months were 1.77±0.10 (n=10) in PHA and 1.96±0.18 (n=10) in ConA, respectively.
