Immunization with nanogram quantities of nitrocellulose-bound antigen, electroblotted from sodium dodecyl sulphate-polyacrylamide gels.

Intrasplenic immunization with antigen immobilized on nitrocellulose (NC) paper results in an immune response with nanogram amounts of antigen without the use of Freund's adjuvant. Comparing the sensitivity of the intrasplenic immunization with intraperitoneal or subcutaneous administration, we found that the intrasplenic method resulted in more positive animals with higher titres than did the other techniques with the smallest amount of antigen (70 ng of bovine serum albumin). With larger amounts of albumin the intraperitoneal method yielded the highest titres. No loss of antigenicity was observed when we immunized with equal amounts of protein separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotted and stained with either Coomassie brilliant blue R 250 or Amido black 10 B.