Determination of deoxyribonuclease activity, particularly of Staphylococcus aureus and Serratia marcesans.
Description: Jeffries et al. described a procedure for detecting the production of deoxyribonuclease by bacteria and fungi. After 18-24 hours of growth on DNA containing agar medium, the agar surface was flooded with 0.1N HCI. A clear zone around growth of the colonies indicated a positive reaction. A correlation between coagulase production and DNase activity was observed by many workers.
Directions per Liter:
Dissolve 42 grams in 800-900ml of ddH2O. Heat with repeated stirring and boil for one minute to dissolve completely. Add additional water to bring the solution to 1L. Dispense into appropriate containers, loosen caps and autoclave for 15 minutes at 121C.
Microbiological Analysis:
Serratia marcescens ATCC 8100; Good
Staphylococcus aureus ATCC 25923; Good
Staphylococcus epidermidis ATCC 12228; Good
Streptococcus pyogenes ATCC 19615; Good
*Results were obtained from type cultures after incubation at 37 degrees C and observed after 18-24 hours.
Storage and Stability:
Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4 degrees C and used within a short period of time.