Use of Bacillus subtilis minicells to demonstrate an antigenic relationship between the poles and lateral cylindrical regions of rod-shaped cells.

Purified minicells produced by Bacillus subtilis div IV-B1 mutants were used to immunize rabbits. Immune serum was obtained that agglutinated minicells and was able to form precipitin lines when reacted with minicell antigens in double-diffusion or immunoelectrophoretic procedures. Antiminicell serum agglutinated rod-shaped B. subtilis cells to long filaments produced by growth of a cell division-defective mutant at restrictive temperature. These findings indicate that minicells are immunogens capable of eliciting the production of antibodies that cross-react with the lateral, cylindrical regions of B. subtilis rods. It appears, therefore, that poles share a common antigen(s) with cylindrical regions of the cell.