Micrology Laboratories ECA CHECK Easygel for Foods and Beverages was developed and formulated to enhance maximum versatility with clarity, ease of use, and interpretation. For normal test samples of many types, they will grow, differentiate, identify, and quantify E. coli, other coliforms, Salmonella spp., and Aeromonas spp. while inhibiting gram positive organisms and some other gram-negative types. Instructions specify a 24-hour incubation period. In actuality, most samples can be accurately read as early as 18 hours incubation time. Interpretation is as follows (the use of a 10X magnifier will facilitate accurate reading of results):

• E. coli colonies will appear as a dark blue color and may have a slight-colored halo
• Other Coliforms will appear as lighter blue-gray colored colonies generally, but may show variation toward purplish/pink depending upon the relative amounts of the various enzymes they produce
• Salmonella spp. grow as ligh green colonies which darken with age (they are indole negative)
• Aeromonas spp. grow as pink (sometimes very light pink) colonies (they are oxidase positive)