PREPARATION AND APPLICATION OF BCG-PPD
BCG—PPD的制备及应用

BCG Purified Protein Derivative (BCG-PPD)was isolated and purified from BCG Culture filtrate by trichloroacetic acid and ammonium sulfate methods. The purity of BCG-PPD was Similar to PPD-S(international standard) and PPD-C(China), but more than that of PPD-CT68 (Canada)and PPD-RT23(Danish). The Delayed-Type Hyperseusitivity(DTH) to BCG-PPD was more sensitivity than other PPD on BCG vaccinated guinea pigs, but less sensitivity than other PPD on Mycobacterium tuberculosis infected guinea pigs. The conversion rate and induration diameter to BCG-PPD was higher than PPD in 333 of 12 weeks after BCG vaccination newborns, but lower than that of other PPD in 97 tuberculosis patients. It was shown that DTH reaction to PPD was more sensitivity in Mycobacteria homogeneous strain vaccinated individual than Mycobacteria heterogeneous strain vaccinated individual. It was demonstrated that BCG-PPD was better than other PPD on observation conversion rates and induration diameter of BCG vaccinated individual. It maybe help to identification BCG vaccinated or tuberculosis infected with DTH of BCG-PPD and PPD in same individual.