Tiêu đề 19. MICROBIAL CULTURE SENSITIVITY TESTING.pdf ✅

PHARMD GURU Page 4 L = The calculated zone diameter for the lowest concentration of the standard curve response line. H = The calculated zone diameter for the highest concentration of the standard curve response line. c = Average zone diameter of 36 readings of the reference point standard solution. a, b, d and e = Corrected average values for the other standard solutions, lowest to highest concentrations, respectively. Two Level Factorial Assay: Parallel dilutions containing two levels of both the standard (S1, and S2) and unknown (U1 and U2) are prepared. Cavities of each of plate are poured with diluted test samples along with standard. Finally, they are kept in the incubator and zone of inhibition is measured. The potency is calculated by the following formula If the potency of the sample is less than 60 per cent or more than 150 per cent of the standard, the assay is invalid and should be repeated using higher or lower dilutions of the same solution. The potency of the sample may be calculated from the expression.