Immunological methods for the agglutination of protoplasts from cell suspension cultures of different genera

Protoplasts from cell suspension cultures of Vicia hajastana Grossh., soybean (Glycine max L.) and brome grass (Bromus inermis Leyss.) were tightly agglutinated by immune sera prepared against them in rabbits. After incubation, the aggregated protoplasts became adpressed over a considerable area of their surface. Antibody prepared against Vicia protoplasts agglutinated both Vicia and soybean protoplasts alone, as well as a mixture of the two. Soybean and bromegrass antibody likewise cross-reacted with and agglutinated Vicia protoplasts. The heterologous reactions were nearly as strong as, and in some cases stronger than, the homologous. When sheep anti-rabbit globulin was reacted with a mixture of the protoplasts previously coated with homologous antibody, agglutination occurred much more quickly and the aggregates could not be dispersed without physical damage. Carbol-fuchsin staining of nuclei showed that Vicia and soybean protoplasts were randomly mixed in the aggregate. The protoplasts were viable and underwent division after the antibody treatment. The immune serum, which presumably contained complement, lysed the protoplasts unless it was heat-treated prior to use.