Abstract: A device for determining the presence and identity of a specific microorganism in a biological sample based on biochemical tests is disclosed comprising a set of containers, each of which contains a reagent for performing an individual biochemical test useful for the identification of microorganisms, the set of containers being assembled on a single supporting member which is imprinted with a series of marks adjacent the containers, which marks are indicative of the expected result of a specific microorganism's performance in each biochemical test using the reagent of each individual container, the series of biochemical test containers, reagents and corresponding marks being sufficient to identify a specific microorganism. Series of marks corresponding to the expected biochemical test results for several specific microorganisms are preferably imprinted on the supporting member, making possible the identification of a single microorganism species from among several possibly present.