the obvious advantages of these units are the need for minimal storage space,the use of less media, the rapidity with which results may be obtained, and the applicability of the results to a computerized dystem for identification of organisms. disaadvantage including difficulty in obtaining the proper inoculum size since some media require heavy inoculation while others need to be lightly inoculated,possibility of media carryover from one compartment to anther,using inoculum of improper age.