Nutrient Solutions, Inorganic and Organic standards, COD vials, SPE disks and filters, GGA Standards for BOD5, and TSS filters, Colitag. Colitag™ is a presence/absence and MPN enzyme substrate test that provides 16-48 hour total coliform & E. coli determinations and detects 1 MPN of total coliform or E. coli bacteria per 100mL water sample. Colitag™ is relied upon by laboratories in more than 24 countries. Aside from the Colitag™ Test Media, CPI International also offers Coliform Sample Vessels and Microbial Testing Accessories.