The Use of Ethyl Alcohol as Precipitant in the Concentration of Antipneumococcus Serum

[摘要] Studies of the solubility of the pneumococcus antibody in alcohol reveal the following:Practically all the protective substance present in the original serum is insoluble in 15 to 20 per cent alcohol at 0°C. The precipitated protein containing both water-soluble and water-insoluble protein can be washed with water to remove the former, and the latter dissolved in salt solution is found to contain protective antibody in practically the same concentration as the original serum. Precipitation with 10 per cent alcohol gives a product in which the immune protein is approximately 80 per cent of the total protein. Irrespective of hydrogen ion concentration from pH 5 to pH 9, if the precipitate is neutralized before diluting, the pneumococcus antibody is insoluble in 20 per cent alcohol. In more alkaline solutions a greater concentration of alcohol is necessary to cause precipitation. Water-alcohol mixtures precipitate the antibody but with an increased amount of inert protein as compared to the precipitate obtained with alcohol mixed with undiluted serum. The use of alcohol as a precipitant in the concentration of anti-pneumococcus serum gives a yield of at least 80 per cent of the protective substance found in the original serum. It has been found possible to dry the active material with retention of immunological characteristics.

[学科分类] 生物科学（综合）