Negative control media device and method for microbiologic biochemical tests

Abstract

A microorganism identification test container comprises a tray member provided with a plurality of integrally formed open wells. A number of the wells are microorganism identification test wells having biochemical test media which in hydrated form permits growth of microorganisms with the generation of a volatile color-forming compound. Another number of wells are negative control wells corresponding to each of the test wells provided and including an inhibitor which in aqueous solution prevents color formation in the negative control wells from the volatile color-forming compound generated in the test wells. The wells are preferably disposed in a number of generally parallel rows or lines wherein one line or row contains a series of biochemical test media and an adjacent line or row contains the corresponding negative control medium for each test. Biochemical test media used in the identification of microorganisms either contain an indicator or generate an indicator upon inoculation with microorganism, that responds to specific microorganism activity with a detectable change in color. Comparison between the negative control wells and the test wells, after inoculation and incubation of the microorganism, indicates the presence of a particular microorganism. Since many of the biochemical test media employ indicators that produce only subtle visually detectable changes in response to microorganism activity, the appearance of the negative control must remain essentially unchanged or subtle changes in the biochemical test wells will be difficult to perceive.

Dependencies are inferred from the claim text.