The preparation and some properties of purified diphtheria toxoid / by Arthur Frederick Watson and Elsie Langstaff.

  • Watson, A. F.
Date:
[1926?]
Catalogue details

Licence: In copyright

Credit: The preparation and some properties of purified diphtheria toxoid / by Arthur Frederick Watson and Elsie Langstaff. Source: Wellcome Collection.

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    will be dealt with in a future publication. For the present work, however, 1 % glacial acetic acid has been used as the precipitating agent and the pre¬ cipitate so obtained subjected to a systematic chemical study. It is of interest here to include data on the amount of precipitate produced by the action of 1 % glacial acetic acid on various types of culture filtrate. The presence of phenol or formaldehyde plays little, if any, part in determining the amount of precipitate formed. Table I gives the results obtained. For the estimations, 300 cc. of the culture filtrate were precipitated with 1 % glacial acetic acid and the precipitate coagulated by heating in a water-bath to 100° for 10 minutes. The solution was then cooled to room temperature and filtered. The precipitate was washed with 300 cc. of distilled water, transferred to a Kjeldahl flask and the nitrogen estimated in the usual way. Table I. Nitrogen precipitable by 1 % glacial acetic acid from various types of culture filtrates. Percentage Type No. Total nitrogen mg./100 cc. Precipitable nitrogen mg./1000 cc. Precipitable nitrogen Non- precipitable nitrogen Peptone X + horse J 3543 442-4 21-7 0-5 99-50 muscle extract Peptone Y + horse J 3558 281-4 50-8 1-82 98-18 muscle extract Peptone Z + horse J 3541 320-0 44-5 1-4 98-60 muscle extract Tryptic digest (a) 3-5 hrs. at 40°. Horse muscle (Watson J 3550 439-6 42-5 0-97 99-03 and Wallace) J 3554 436-8 40-9 0-94 99-06 (6) 2-5 hrs. at 37°. (Watson and Lang- TA 20 250-5 30-27 1-21 98-79 staff) TA 21 245-0 11-93 0-49 99-51 (c) 72 hrs. at 15°. (Watson and Lang- TME 99 180-6 33-6 1-86 98-14 staff) TME 100 277-4 11-7 0-42 99-58 In all cases the amount of nitrogenous material removed from the filtrate is very small and it would appear that the active principle, whatever its nature, must form only a small percentage of the total material of the culture filtrate. The general technique for preparing purified toxoid. The method is essentially that of Watson and Wallace [1924, 2] and con¬ sists of the acetic acid precipitation of the culture filtrates of C. diphtheriae which have been treated with formalin. If completely atoxic solutions are required the formalised filtrates are incubated until the m.r.d. [Glenny and Allen, 1921] of the filtrates is negligible. The distribution of the active principle between the precipitate and supernatant fluid varies with the type of filtrate used and also with the presence of preservatives or other substances which may affect the stability of the toxoid molecule. The details of the large scale methods for precipitating culture filtrates and the working up of “super-