1984 Volume 32 Issue Supplement2 Pages 99-111
The concentrations of TA-058 in the body fluids were determined by the cylinder-plate assay, the disc-plate assay and the agar well assay methods using E. coli ATCC 27166, M. luteus ATCC 9341 and B. subtilis ATCC 6633. The most suitable method may be chosen depending on the sample concentration and volume. The clear and large inhibitory zones were obtained by adjusting the pH of assay medium to 6.0. The cylinder-plate method was most sensitive, which was followed by the agar well and the disc-plate methods in the sensitivity.
The inhibitory zone diameters of TA-058 in human or various animal serum and bile were found to be smaller than those of in M/15 phosphate buffer. However, when the specimens were diluted over 5-fold with the phosphate buffer, the potency of TA-058 was completely recovered. Thus, the concentrations of TA-058 could be determined by using standard curves which were prepared with the same body fluids or the phosphate buffer as a diluent. Since the potency of TA-058 in the serum and bile decreased by the preservation in a refrigerator (5°C) for one day, the potency in these specimens desire to determine rapidly. The potency of TA-058 in the body fluid was, however, stable at-20°C for 7 days. TA-058 was also stable in human urine and did not affect the inhibitory zone diameter.
