Diphtheria toxoid-antitoxin floccules / by A.T. Glenny and C.G. Pope.

  • Glenny, A. T.
Date:
[1927?]
Catalogue details

Licence: In copyright

Credit: Diphtheria toxoid-antitoxin floccules / by A.T. Glenny and C.G. Pope. Source: Wellcome Collection.

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    injected intracutaneously with Schick toxin each week commencing three weeks after the initial injection. Table I. recording the results of the experiment gives the serial numbers of the Schick injections first yielding a negative reaction, i.e. the immunity index. Table I. Showing the immunity index for a series of toxoid-antitoxin floccules prepared from different batches of toxoid with different amounts of antitoxin. Toxoid. Lf value. Units of antitoxin per c.c. of toxoid. Immunity index. 1-0 c.c. 5-0 c. c. A 20 14 2 3 3 3 4 4 20 5 7 3 3 6 32 4 7 9 ... ... B 9 6 2 3 5 2 3 5 9 4 2 3 3 12 over 10. ... ... • . • C 14 10 2 2 3 4 14 5 over 6 10 2 3 over 4 20 6 7 over 10 4 7 over 10 It will he seen from table I. that toxoid-antitoxin floccules prepared with the minimum amount of antitoxin are better antigens than those prepared with more antitoxin. It will be further seen that with these floccules doses of TO c.c. and of 5*0 c.c. appear equally efficient, thus confirming the earlier work of Glenny, Pope, Waddington and Wallace (1926). In this connection it must he pointed out that the “ immunity index ” method measures the rapidity of production of immunity rather than degree of immunity produced. The amount of antitoxin produced and the degree of tolerance to toxin ultimately reached by the guinea- pig injected with 5-0 c.c. doses may be higher. It appears reasonable to suggest that rapidity of immunisation in the human subject as indicated by a negative Schick reaction is of more importance than the attainment of a high level of immunity. Further experiments were devised to explore methods of improv¬ ing the antigenic values of the floccules. Bamon (1923) recovered antitoxin by freeing toxin floccules from salt, treating them with dilute acid and heating for one hour at 58° to 60°. For our work it was necessary first to determine the optimum pH for the removal of antitoxin. Acid or alkali was added to a series of quantities of a suspension of toxoid-antitoxin floccules to adjust them to different hydrogen ion concentrations. Owing to the unbuffered nature of the material it was necessary first to plot the accompanying titration curve electrometrically; the quinhydrone electrode with the direct reading pH meter described by Pope and G-owlett (1927) was used. This curve determined the amount of acid or alkali to be added to the larger samples which were then checked electrometrically; by this method