National Institutes of Health Bulletin Volume 132-139

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 Excerpt: ...made from two agar slants," or "1 e. c. of a beef broth culture." Unfortunately such statements are still appearing in bacteriological literature, but they are fast becoming meaningless. Bacterial cultures are not comparable unless grown under identically the same conditions for the same length of time, and inoculated from the same kind of parent culture. In the results presented in this paper effort has been made to lay special emphasis upon these points. Early in our experience with the mouse protection test for determining the potency of antipneumococcic serum we realized the inadequacy of the test in so far as the so-called "border-line" serums were concerned. Not so plainly evident are the weak points of such a test applied to a very good serum or to a very poor one--that is, in either case fairly constant results may be obtained. THE PROTECTION TEST. The complete details of the potency test for antipneumococcic serum as conducted at the Hygienic Laboratory are given in the Public Health Reports for November 21, 1919, page 2663. In brief the method is as follows: White mice are selected weighing from 15 to 20 grams. They are injected intraperitoneally, the serum first and the culture immediately afterwards. The serum is diluted with saline solution (0.85 per cent) so that 0.2 c. c. is contained in 0.5 c. c. of the dilution. The culture is diluted with broth (plain or glucose) so that 0.1 c. c. is contained in 0.5 c. c. of dilution. At the same time 8 mice are inoculated with the culture alone highly diluted. These culture control mice receive 0.00,000,1 c. c., 0.00,000,01 c. c., 0.00,000,001 c. c., and 0.00,000,000,1 c. c. of the culture used for the teat, 2 mice to each dose. To maintain the organisms in an actively virulent c...