Studies on the dinitrophenylated lymphocytes in guinea pig painted with DNCB

The number of DNP group-bearing lymphocytes in the regional lymph node, thoracic duct and peripheral blood was determined at various time intervals after painting normal guinea pigs with DNCB by the immunofluorescent method using anti-DNP antibody. The incidence of such cells in the regional node was maximal at 12 hours whereas in the thoracic duct and peripheral blood the maximum incidence was found at 0.1-2 hours after painting. Unreacted DNCB was demonstrated in both the thoracic lymph duct and the blood at least for 12 or 24 hours respectively following exposure to DNCB. The authors therefore suggest that DNCB reacts directly in vivo with the lymphocyte cell membrane of guinea pig following epicutaneous application of the chemical.