(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.

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    These experiments on the immunising value of concentrated diphtheria toxin, as compared with that not so concentrated, are being continued. PUKIFICATION OF TETANUS TOXIN. Owing to the vigorous digestion of the broth constituents by the tetanus organism the concentration of toxin per mg. nitrogen obtained by ultra¬ filtration followed by pressure dialysis is in this case greater even than in that of diphtheria cultural filtrates. The rapidity of filtration is, too, for the same reason, much greater. The slight precipitate obtained on acidifying the dialysed material is, as has been already stated, not toxic. This curious difference between diphtheria and tetanus toxins must be of considerable theoretical significance. In the tests given below the animal used was the mouse. Experiment 1. An experiment has been described [Walpole, 1915, p. 288] where comparative tests of the porosities of two bags showed that no toxin could be detected in one of the filtrates and very little in the other. A dose of 0*0005 cc. of the original material placed in the bag caused death on the 4th day. Experiment 2. Toxin BDC (0*0005 cc. death on 4th day); 30 cc. were concentrated to one-seventh the volume with continual change of water outside, and diluted again to its original volume: no change in M.L.D. could be detected. A small precipitate obtained by acidifying and centrifuging an aliquot portion was found to be non-toxic. Experiment 3. 190 cc. of toxin BDC were reduced to 6 cc. as above. Of this 0*00005 cc. gave death on the 3rd day 0*00002 cc. ,, ,, 7th ,, that is to say, that the toxin was concentrated about twenty times and the volume reduced to one-thirtieth. Experiment 4. Toxin BDA (L+ dose 0*05 cc.); 10 cc. of this were reduced to about 3 cc. and then made up to the original volume with physiological saline solution. The L+ dose was found to be unaltered. Experiment 5. 10 litres toxin BKA (1 cc. contains 3*7 mg. nitrogen) gave in the apparatus described by Walpole [1915, Fig. 2] in six days 9630 cc. of ultrafiltrate divided between five bags. Tests on these filtrates showed that one bag only allowed a detectable amount of toxin to pass through (M.L.D. 0*4 cc.). Twenty-four hours’ pressure dialysis followed, and then