The value of Douglas's medium for the production of diphtheria toxin / by Percival Hartley.
- Percival Horton-Smith Hartley
- Date:
- [1922?]
Licence: In copyright
Credit: The value of Douglas's medium for the production of diphtheria toxin / by Percival Hartley. Source: Wellcome Collection.
3/12
![THE VALUE OF DOUGLAS’S MEDIUM FOR THE PRODUCTION OF DIPHTHERIA TOXINA By Percival Hartley. From the Wellcome Physiological Research Laboratories, Herne Hill, London. Shortly after the outbreak of war, it became evident that Witte’s Peptone would soon be unobtainable for bacteriological work. The stocks of this material were limited, the demand for culture media increased enormously, and the discovery of a substitute became a matter of urgent necessity. Douglas (1914^^) described a simple method for the preparation of nutrient broth which was widely adopted. Although evolved in the first instance as a war emergency measure, and perhaps regarded as such, the method then introduced of preparing media by the action of enzymes on proteins has been shown by numerous other workers to be so convenient and economical and to yield such excellent results, that it has found a place in the permanent routine of many bacteriological laboratories. Douglas’s method consists in the digestion of ox muscle with trypsin. The digestion is allowed to proceed for two or three hours: the mixture is then acidified with acetic acid and brought to the boil. Any un¬ digested muscle is filtered off, salts are added to the filtrate and the reaction adjusted. The medium thus obtained is distributed into suitable containers and sterilised. In January 1915, Harden and myself (1915working at the Lister Institute, repeated Douglas’s experiments and confirmed his results. We found that organisms grew luxuriantly on this medium and, moreover, that it was suitable for the preparation of both tetanus and diphtheria toxins, in the latter case a minimum lethal dose of 0-001 c.c. being obtained. On account of other duties in connection with the war, it was not possible to continue this work at the time. In September 1919, the subject was taken up again by one of us (P. H.), and during the last two years medium prepared by a method closely resembling that of Douglas has yielded high-grade toxin. Since the statement has frequently been made that medium prepared in the laboratory by the action of enzymes on proteins is unsuitable The substance of this paper was communicated to the Meeting of the Pathological Society of Great Britain and Ireland, at Birmingham, July 1921. [Received for publication, June 8, 1922.]](https://iiif.wellcomecollection.org/image/b30623388_0003.jp2/full/800%2C/0/default.jpg)
