This 1975 image depicts an analytical profile index, or API, test strip, which had originally been manufactured in the United States by Pierre Janin of Analytab Products, Inc., but is now manufactured by bioMérieux. This particular strip had been inoculated with inocula of Clostridium ramosum, an anaerobic bacterium normally found in the human intestinal tract. This API strip consists of twenty small reaction tubes, known as cupules, each containing a unique reagent, which based upon the metabolic characteristics of the sample bacterium, will produce a color change in the tube. These tests provide for the identification of a limited number of Gram-negative, Enterobacteriaceae, or non-Enterobacteriaceae bacteria, i.e. C. ramosum.