Towards an improved sterility test.

The sterility test is generally recognized as a flawed test for its stated purpose. Since the original description in 1932, this test has generated controversy as to its role in product quality testing and in terms of means to improve the assay. As early as 1956 Bryce published an article describing the two critical limitations of this test (1). He put forward that the test was limited in that it can only recognize organisms able to grow under the conditions of the test, and that the sample size is so restricted that it provides only a gross estimate of the state of “sterility” of the product lot. Other concerns about the sterility test (e.g., choice of sample size, choice of media, time and temperature of incubation) were extensively reviewed in an article by Bowman (2).