(1) Notes on colloidon membranes for ultrfiltration and pressure dialysis / by G.S. Walpole. (2) Detection and concentration of antigens by ultrafiltration, pressure dialysis, etc., with special reference to diphtheria and tetanus toxins / by A.T. Glenny and G.S. Walpole.

  • Walpole, George Stanley.
Date:
[1915?]
Catalogue details

Licence: In copyright

Credit: (1) Notes on colloidon membranes for ultrfiltration and pressure dialysis / by G.S. Walpole. (2) Detection and concentration of antigens by ultrafiltration, pressure dialysis, etc., with special reference to diphtheria and tetanus toxins / by A.T. Glenny and G.S. Walpole. Source: Wellcome Collection.

    19/30 (page 299)
    all other antigens with which experiments were subsequently tried. These unexpected results, in flat contradiction to those of Baroni [1911] for example, who found diphtheria and tetanus toxins to pass through the collodion membranes he employed, form the basis of the concentration methods here put forward. The various experimental difficulties have disappeared as the result of experience, but, so far, it is only in the case of diphtheria toxin that precipitation by a trace of acid after the removal of the salt can be used as an effective short cut to a purification of the antigen. The invariable result, so far as my experience goes, that antigens do not pass through these membranes suggests their employment not only for routine toxin purification, but in addition as a laboratory test to form a first opinion on the specificity or otherwise of the toxic constituents of any cultural fluid. The Purification of Diphtheria Toxin. A batch of diphtheria toxin is appraised by the immunologist by its “binding unit” content per cc., a quantity which for all purposes is most readily measured as the L+ dose, though this would not necessarily be so if the original media were not similar or had not disintegrated, during the growth of the bacillus, on similar fines. Also, the reservation is made that the “binding units per cc.” of these broths are by no means proportional to their utility: rather some such scale as the following is taken: L+ dose Use for immunising 0-15 cc. “excellent” 0-30 cc. “good” 0-50 cc. and over “unusable.” In other words poor toxin cannot be made to act as good toxin simply by taking more of it, for experience has shown that the development of anti¬ toxin in the horse is greater when the effective immunising material is inter¬ fered with in its action as little as possible by accompanying nitrogenous matter. It may therefore be taken as a working hypothesis, remembering that the experience of the immunologist is the final and only appeal, that, providing the loss of toxin is minimal, the extent to which the binding units per milli¬ gram of nitrogen is increased by this purification process is some sort of measure of its efficiency. When the material accompanying the toxin is so far reduced as to be physiologically of no importance in the dose accompanying the greatest toxin injection given, it is obviously not a true measure because