Absorption and Elution of Antibodies from Various Antisera.

Frankel and Olitzki 1 showed that by specific absorption and elution it is possible to obtain antibodies free from protein by absorbing the antisera with kaoline, centrifugalizing and then eluting the kaoline absorbate with appropriate eluates. The eluates thus obtained are free from protein, in so far as they can be demonstrated by sensitive chemical tests, but contain active antibodies.

We here report experiments dealing with the elution of antitoxin, agglutinins, complement-fixing and lytic amboceptors and the behavior of these eluted antibodies. Since it is generally accepted that biological sensitization is a more sensitive test for proteins than the most sensitive chemical test, we attempted to ascertain by this method whether the eluates contained demonstrable proteins. The eluting fluid consisted of a 2% solution of glycocol with varying concentrations of sodium chloride. The technique was as follows:

Equal parts of antiserum (diluted 1:10) and kaoline were thoroughly shaken, allowed to stand 24 hours at 37°C. and centrifugalized. The kaolin-protein sediment was then resuspended in the eluting fluid and the suspension kept at 37°C. for 48 hours, then centrifugalized and the supernatant fluid tested for antibodies. The antitoxin content of the protein-free eluates was determined by the intracutaneous neutralization test employed by Roemer 2 ; the content of agglutinin, complement-fixing and lytic amboceptors was measured by the methods described by Olitzki. 3

The results showed that the largest amounts of antitoxin and of the flagellar typhoid agglutinin are obtainable in eluates made with 2% glycocol in 1 to 2% sodium chloride solution, while the largest amounts of the somatic agglutinins as well as the lytic and complement-fixing amboceptors were obtained in eluates made with 0.2 to 0.8% solution of sodium chloride. Attempts to elute by this method the complement-fixing amboceptors from luetic sera giving a strong positive Wasserman and Kahn reaction yielded negative results.