Division of Radiooncology, Deutsches Krebsforschungszentrum, 69120 Heidelberg, Germany
The preparation of soluble PAP complexes follows the method of L A STERNBERGER et al. (1970). First, specific immune precipitates are obtained by mixing anti-peroxidase with peroxidase (HRP). Then, precipitates are washed in saline, followed by resuspension in saline containing four times the amount of HRP used for precipitation and by acidification to pH 2.3. After subsequent neutralisation and removal of undissolved complexes, soluble PAP complexes are finally obtained and purified from free HRP by ammonium sulfate precipitation.