摘要：All types of tuberculin, crude and pure alike, have in the past been assayed by “matching” the skin reactions they produce in sensitized animals with those produced by the International Standard for Old Tuberculin; furthermore, a variety of sensitizing antigens have been used. Such “matching” assays are not easy to analyse statistically. An assay is described, based on the linear relationship between the diameter of the skin reaction and the logarithm of the dose of tuberculin. This type of assay is shown to be precise. It eliminates the need for preliminary titrations and provides information about the slope of the dosage-response lines, and it yields fiducial limits of error from the internal evidence of the assay. Using this method, a comparative study is made of the effects of varying both sensitizing antigens and test allergens. It is shown that there is sufficient heterogeneity among these different types of tuberculins to make invalid their comparison in terms of a single standard, namely, the International Standard for Old Tuberculin. Full text Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.1M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References . 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002
