Colitag™, made by CPI International, is a ready-to-use ONPG/MUG based test, which can be added directly to a liquid or semi-liquid sample. If coliforms are present, ONPG will produce a distinct yellow color. If E. coli is present, the sample will fluoresce a bright blue color under long-wave (366nm) UV light. Incubation of the test is performed at 35°C for 22-26 hours.

Benefits of Colitag include:

• Allows you to run a traditional Presence/Absence (P/A) or MPN format
  
  
• Detects 1 CFU of total coliform or E. coli bacteria per 100ml water sample
  
  
• Resuscitates chlorine injured bacteria
  
  
• Provides selectivity with growth inhibitors without affecting recovery of
  target organisms
  
  
• Brighter blue fluorescence eliminates questionable positive E. coli results
  
  
• Simultaneously provides 24-hour fecal coliforms and E. coli determinations
  

Left bottle: Negative result Middle bottle: Positive for coliform Right bottle: Positive for E. coli by fluorescence

Colitag™ is capable of resuscitating and detecting even single cells of severely injured E. coli and coliforms. In March of 2004, Colitag™ earned US EPA approval for use as a presence-absence test in drinking water and approval for use as an enumerative test in MPN format in May of 2005.

Colitag™ is available for use in municipal and bottled water testing, beverage waters and other QC coliform monitoring testing. Preliminary testing has also shown promising results for monitoring shellfish meats and shellfish-growing waters, as well as for waters growing alfalfa sprouts.


Colitag is now available from Hardy Diagnostics.