(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.

    21/30 (page 301)
    At the time of writing two sets of apparatus [Walpole, 1915, Fig. 3] each consisting of eight bags which were set up some months ago are still in use. One has handled over 100 litres; the other about 44 litres, of which two small batches were worked out more or less completely. Details of concentration experiments. March 12th to April 1st. Using the continuous apparatus [Walpole, 1915, Fig. 3], 12 litres of diphtheria bouillon, J 2520 (L+ dose = 0*40 cc.: nitrogen = 2-8 mg. per cc.) gave, in 20 days, 8500 cc. of pressure dialysed material (nitrogen — 1*96 mg. per cc.). The process was not hurried in any way; nothing was drawn off for three days, then 500 cc. per day were collected through the run, and then a couple of days allowed to elapse before all the bags were emptied. The excess of pressure used was 0-3 atmosphere and the consumption of the dialysing fluid, 0-30 per cent, phenol in distilled water, ten litres per day. After acidification the precipitate, representing twelve litres of the original bouillon, was dissolved in alkali and diluted to 250 cc., giving a solution whose L+ dose was found to be 0-012 cc., and the nitrogen per cc. 2-80 mg. The result may be roughly stated that, with a loss of 30 per cent., the binding units per mg. nitrogen and also the binding units per cc., have been increased 33 times. The previous batch of toxin treated by this set of collodion bags was J 2530, of which 11-5 litres (L+ dose 0-40 cc.: nitrogen 4-6 mg. per cc.) gave 230 cc. of concentrated material (L+ dose 0-01 cc.: nitrogen 6 mg. per cc.) representing a yield of 80 per cent. When the same set of bags had handled 50 litres of material whose L+ dose was 0-4 cc., a sample of dialysate from C was collected. They were then lifted clear from the glass jars containing them and some of the ultrafiltrate dripping from them collected (that collected in the first hour or two was, of course, discarded). Neither of these solutions interfered with the increase of weight of the guinea pig when injected in a dose of 1 cc. The lost toxin, therefore, does not pass through the bags, nor is it to be found in the supernatant fluid above the precipitate produced by acidi¬ fication. It would seem probable that it represents destruction by light, or by being left at room temperature and in a state of increased purity at a reaction which is probably not that at which it is most stable, at s’ome stage in the process. Experiments on this point are in progress. Should the loss be actually in the filter itself the recovery therefrom of a highly toxic material may be anticipated.