Immunochemical demonstration of plasminogen phenotypes using electroblotting.

The polymorphism of plasminogen (PLG) was analysed by isoelectric focusing on polyacrylamide gels, followed by electroblotting. For analysis, neuraminidase-pretreated sera were used. In a random sample of 500 unrelated individuals from east Westphalia 8 phenotypes were observed. The allele frequencies were: PLG*1 (A), 0.708; PLG*2 (B), 0.274; PLG*3 (A3), 0.013; PLG*V, 0.005. The family data (300 mother-child pairs) confirmed the hypothesis of autosomal codominant inheritance. PLG phenotypes could be determined in 1-year-old bloodstains (cotton and glass) that had been stored at +4 degrees C and -20 degrees C. The PLG phenotypes could clearly be demonstrated in sera diluted 1:4. The phenotype 1 (A) could still be detected in dilutions of 1:6. The theoretical exclusion rate was calculated to be 22.6%.