Studies on the Berkefeld-Filtration of Complement

Abstract

INTRODUCTORY.IN view of the divergent results obtained in recent work dealing with the effect of Berkefeld filtration on the haemolytic complement of serum, I think that the publication of the results which I have obtained during some investigations, which I have been carrying out on the inactivation of complement by shaking, may not be without value.Muir and Browning (1909) found that by filtration through a Berkefeld filter the complement of a guinea-pig serum is retained by the filter to a large extent-sometimes indeed completely,--but if more serum is filtered it passes through. Neufeld and Andrejew (1909) and Andrejew (1910) found that out of all immune bodies in serum, complement is the most completely retained by filtration through Kieselguhr. Andrejew showed further that the relative loss of complement was considerably increased when the serum was previously diluted, no more complement passing through if the serum was diluted 1:10. A detailed investigation of the filtrability of complement was then undertaken by P. Schmidt (1911P. Schmidt ( , 1912. He confirmed the observation of Andrejew in regard to the effect of dilution. His explanation was that the colloidal complement ferment, which he considers to be an entity, becomes less dispersed by dilution and therefore more easily retained by the filter. If undiluted, the serum proteins, especially the albumins, have a protecting influence upon the complement, which passes through the filter in the course of prolonged filtration, because the albumins cover the whole Kieselguhr