Convenient Assay for Staphylococcal Nuclease by the Metachromatic Well-Agar-Diffusion Technique

Convenient assay for staphylococcal nuclease by the metachromatic well-agar-diffusion technique.

The metachromatic agar-diffusion (MAD) microslide technique was adapted for quantitative assay for staphylococcal thermonuclease in heterogeneous systems, such as milk and broth. When an enzyme-containing solution was placed in a well cut in the agar, a bright pink halo was obtained. The diameter of the pink zone of hydrolysis was related to time and temperature of incubation and to nuclease co...

Metachromatic agar-diffusion methods for detecting staphylococcal nuclease activity.

Based on the metachromatic property of Toluidine Blue O, three, convenient agar-diffusion methods have been developed that enable detection of the nuclease of Staphylococcus aureus at concentrations as low as 0.005 mug/ml in agar and broth cultures. The interactions of agar and deoxyribonucleic acid with Toluidine Blue O are discussed.

Micro diffusion agar precipitin technique convenient for viewing and recording.

Micro gel diffusion reactions, though used extensively in recent years, still present problems in viewing and recording. Direct photographs of these reactions, that usually must be enlarged, are not always satisfactory. Better results are obtained by using the dried, stained film as a negative and printing directly from this. Microscope slides are most often used, but glasses (2 by 2 inches) su...

The Study of African Horse Sickness Virus by the Agar Double-Diffusion Precipitation Test l-Standardization of the Technique

Agar diffusion method for the assay of colicins.

An agar diffusion method for the assay of colicins A, B, D, E(2), E(3), and K is described. The assays were performed in large, square pyrex dishes that contained an agar layer seeded with an indicator organism sensitive to the colicin. The samples were applied to the agar in steatite beads positioned in a randomized sequence. The plates were stored at 4 C for 24 hr to allow the colicins to dif...