Abstract
A new plate method for counting spores of C. botulinum is outlined. The method is based on (1) the use in the medium of HCO3, which breaks the dormancy of these spores, and (2) the use of a Petri dish made anaerobic with a glass plate and anaerobic agar overlying the inoculated medium. The method requires only 24-36 hrs. It has been tested with 8 cultures of C. botulinum and putrefactive anaerobe No. 3679. The method gave significantly higher counts on spore suspensions than have been obtained with other methods in other laboratories.