Problems encountered with the capillary tube immunodiffusion method for detection of botulinal toxin.

By using antitoxin specific for the neurotoxin molecule, the capillary tube immunodiffusion method did not detect low levels of crystalline toxin. Reactions described earlier with crude toxin and less specific antitoxin were probably due to nontoxigenic botulinal antigens.

Development of culture vessel for sterility testing of bandages and other medical devices.

A cylindrical glass culture vessel equipped with a vented nylon closure was developed and evaluated for sterility testing. The sterility testing cylinder (STC), made in 2 sizes, accommodates 250 or 400 mL culture broth. A tight-fitting, skirted nylon cap protects the upper part of the cylinder, and a membrane filter in a recessed opening allows venting during autoclaving and ensures sterility during removal and replacement of the cap.

Detection and growth of enteropathogenic Escherichia coli in soft ripened cheese.

The organism most frequently encountered during the 1971 outbreak of enteropathogenic Escherichia coli (EPEC) in soft ripened cheese was a strain that failed to ferment lactose broth within 48 h. Since existing methods for E. coli are dependent upon fermentation of this sugar, such strains can remain undetected, particularly when present in low numbers.