Frequency of Single Spleen Cells from Hyperimmune Rabbits Producing Antibody of Two Different Specificities

Abstract

Spleen cells from rabbits hyperimmune to bovine serum albumin (BSA) were assayed for their ability to produce hemolytically inefficient (7S) antibodies of two specificities by the hemolytic plaque assay. When assayed against a mixture of rabbit red cells conjugated with either of two cyanogen bromide fragments of BSA, only 1 of 37,568 antibody-producing cells could have been a double producer, suggesting that a given single cell can produce antibody of only a single specificity. These results were discussed in the light of previous studies with single cells and in relation to the two main theories of the origin of antibody diversity.