A Practical Method for Concentrating Chill Free Pneumococcus Antibodies from Sera Without Use of Salt Precipitations.

Abstract

Avery 1 and Felton 2 showed that pneumococcus antibodies were irregularly precipitated from the antisera by simple dilution of distilled water. Banzhaf 3 showed that by fractioning the antisera with sodium sulphate and also with ammonium sulphate the antibodies could be precipitated from the dialyzed globulin on dilution with distilled water. Felton, 4 using the sodium sulphate method to recover the antibodies from the dialyzed globulins, found that at this stage the chill producing substance could be eliminated by dilution. He added sufficient normal sodium sulphate to a point where most of the antibodies were held in solution (the amount depending upon the length of dialysis). He then corrected the reaction to pH 4.8, at which point antibodies are in solution and a considerable amount of inert proteins together with the chill producing substances are precipitated.

It occurred to us that if we diluted antisera to a point where there was a definite precipitate and corrected the reaction to about pH 5, the small amount of antibodies precipitated would become soluble and the inert protein together with the chill producing substances would precipitate. This we found did occur. We obtained the same results without dilution by dialyzing the antisera practically free from salts and then adding sufficient sodium chloride or sodium sulphate to have a normality of about 1/20 and correcting the reaction to pH 5-5.1.

These methods were reported by Dr. William H. Park at the Harben Lectures in London October 10th, 1930, and are as follows: The cold antisera containing 0.4% trikresol or 0.5% phenol are diluted with cold distilled water, one part serum to 3 parts of distilled water, a definite precipitate occurs. When corrected to pH 5-5.1 using gamma dinitrophenol 0.025 % solution as indicator, precipitated material will almost completely dissolve, followed immediately by a reprecipitation of inert protein together with the chill producing substances.