THE USE OF CAPRYLIC-ACID FOR THE EXTRACTION OF THE IMMUNOGLOBULIN FRACTION FROM EGG-YOLK OF CHICKENS IMMUNIZED WITH OVINE ALPHA-LACTALBUMIN

The extraction and purification of serum-derived immunoglobulin fracti on in the egg yolk of hens by the combined treatment of the raw egg yo lk with caprylic (octanoic) acid and ammonium sulphate is described. T his simple two-step method proved to be both rapid, reproducible and s uitable for batch processing of pooled egg yolk. The method recovered in excess of 130 mg of immunoglobulin per egg yolk. Two chickens were inoculated at two weekly intervals with 100 mu g each of ovine alpha-l actalbumin over a ten week period. The alpha-lactalbumin antigen was p urified by a hydrophobic-interaction chromatographic procedure and fur ther purified by a gel excision-elution process. No precipitating anti bodies could be demonstrated in gel diffusion techniques with this ant ibody. The specificity and specific activity of the antibody were moni tored by western blotting and demonstrated the presence of highly spec ific antibodies to ovine alpha-lactalbumin in the treated egg yolk. Th e extraction procedure had no adverse effects on antibody titre. We co ncluded, and confirmed previous reports, that the use of chickens for the production of highly specific antibodies to mammalian proteins wit h particular reference to milk proteins presented numerous advantages over conventional procedures.