[Conjugation and isolation of POD labelled antibodies [author's transl)].

1. The POD content of the antibody/POD conjugate was measured by means of a method according to Møller and Ottolenghi (1966). Following the incubation of H2O2-benzidine solution the intensity of the yellow-green staining was registered at 410 nm. This method can be applied in the enzyme immunoassay too. 2. For every new test system the optimal antibody/POD ratio of the conjugate has to find out. Conjugates with a IgG/POD ratio in the range of 1 : 0.432--1.114 proved valid in cytological studies. 3. Precipitation, centrifugation, washing, and dialysis did not lead to a reduction of the enzyme activity. 4. In order to decrease nonspecific reactions by conjugate was separated from free POD by means of NH4SO4 precipitation or Sephadex G 200 chromatography. Additionally, nonconjugated antibodies and free POD were separated chromatographically by means of Biogel A 0.5.