Standardization of anti-dysentery (shiga) serum. 2

  • O'Brien, Richard Alfred, 1878-1970.
Date:
[1925?]
Catalogue details

Licence: In copyright

Credit: Standardization of anti-dysentery (shiga) serum. 2. Source: Wellcome Collection.

    5/8 (page 86)
    Varsovie standard kindly sent us by Prof. Kolle and Prof. Hirszfeld respectively. “A” was a concentrated serum, the others unconcentrated. It will be seen that the range of values is undesirably wide. At present it is possible for a clinician to purchase and use two samples of commercial anti¬ dysentery serum which bear no indication on the label, and therefore would be presumed to be of equal “value,” and yet when using the weaker serum he would be giving -g^th or g-^th of the antitoxin contained in the stronger serum. It appeared to be desirable to find out how accurately one could titrate the antitoxic value of a standard serum if a moderate number of mice were used. From a review of our general results we had formed the opinion that we might be able to distinguish sera differing by 20 per cent, in value. Two dilutions of a serum of known strength were made by mixing with normal horse-serum so that they contained 80 per cent, and 64 per cent, of the original serum, and the undiluted serum and the two dilutions were numbered and handed over for test. The strength of the undiluted serum was known, but the identity of the three samples was throughout concealed from the tester. Each serum was tested at three points at 20 per cent, intervals from one another, and the test was repeated three times, the samples being re-lettered between each test. Table IV shows the results obtained. A figure in the table represents the day of death of a mouse, L indicates that the mouse lived. Table IV.—Tests on three Dilutions of Serum. Test-dose 0'2 mgm. 3 A. Serum c.c. S' Identification by 0-008 0-0064 0-005 tester. ls£ test. Sample labelled A • LLLLL LLLLL 3444L 80 per cent. 5, 55 B • 45LLL 33444 34446 64 „ c • 6LLLL LLLLL 457LL 100 „ 2nd test. Sample labelled A • 6LLLL 3445L 1133L . 64 per cent. » » B • LLLLL 45LLL 244LL . 80 „ „ C • LLLLL LLLLL 3LLLL 100 3rd test. Sample labelled K • 36LLL 5LLLL 3345L . 80 per cent. 55 5 5 B • 6LLLL 4LLLL 33444 . 64 „ „ M • LLLLL 14LLL 3LLLL 100 „ Summary. Dose c.c. 0-008 0-0064 0-005 Serum. 15 mice at each dose. Mice protected. 100 per cent. 14 . 13 10 80 3? 13 . 12 4 64 33 11 . 5 1 In the first test sample C appeared to be somewhat stronger than A, one death on the sixth day at the highest dose being considered accidental, and B