|
Currently, the microbiological methods are used to assay the antibiotics and its residues in animal products. There must be test organisms. Non-spore test organi•ms must be prepared freshly and counted before being used. These methods are too complicated.
To solve this problem we had tried to preserve the test organism by means of a gelatin-disc method. Sarcina lutea ATTCC 9341 had remained (l.35x108cells/disc) as they were after being preserved for 14 months (the cell count was 1. 92 x 108 cells/disc before preservation). This study had proved to be satisfactory in terms of preservation. The potency assay of penicillin met the requirements of the Japanese method, but the inhibition zone of low concentration of tylosin was a little narrower but an increase in the amount of medium will meet the requirement. Thus the assaying of the potency has become very convenient because it only needs one disc to mix 100ml medium. We, the-refore, can deduce that the other non-spore test organisms can also be preserved by this method.
|