A quick method for the estimation of the potency of tuberculin purified protein derivative in guinea pig.

By the statiscal analysis of the data the linear regression equation and standard deviation of the dose response function of the Hungarian Reference Purified Protein Derivative of Tuberculin (HR--PPD) have been determined. From the values of reaction diameters of the HR-PPD and of their standard deviation a diagram was plotted that can be used to estimate the identity of test material by comparison with the reference preparation. The diagram meets the condition that the limits of the standard deviation of the reference and test materials together are wider than the predetermined limits of +/-20%. The inaccurate titrations can be detected with its help at once. Using the diagram, the potency of test material can be promptly estimated in the biological assay of tuberculin made in guinea pig.