What Is Colitag™?

Colitag™ is a 16-48 hour water test (P/A and MPN) that detects as few as 1 MPN of E. coli and other coliform bacteria in 100mL of water.

Colitag™ is a US EPA approved for use as a presence absence test and in the Most Probable Number (MPN) format as specified in Standard Method 9221 for compliance monitoring of total coliforms and E.coli in drinking water.

How Does Colitag™ Work?

Colitag™’s strength lies in its ease of use. Simply add Colitag™ to your 100ml sample, incubate for between 16 & 48 hours, use a simple visual check for coliforms in the first instance, then a fluorescence check to determine E.coli bacteria presence. For a more detailed overview please refer below to flowchart.


  • US EPA
  • SANS 5221:2018 (Ed. 4.05)

Benefits of using Colitag™

  • Less than 1 minute hands on time (20 samples in less than 20 minutes) to perform a test
  • Simultaneously detects both total coliforms and E. coli in just 16 hours with NO confirmation testing required
  • Enzyme Substrate Technology identifies coliforms and E. coli specifically
  • Detection limit of 1 CFU/100ml
  • Detects both MUG Positive and MUG Negative (0157) E. coli
  • Suppresses 1 million heterotrophs per 100ml
  • No subjective interpretation as found in the conventional methods
  • No media preparation, glassware, filtration equipment, or colony counting required
  • 90% less equipment costs compared to membrane filtration
  • Minimises work in the evenings and over weekends
  • 18 month shelf life from date of manufacture and storage at room temperature
  • New stick pack provides an ecologically greener solution

Science Behind Colitag™

Colitag utilises enzyme substrate technology for the simultaneous detection and enumeration of total coliform bacteria and E. coli in potable and non – potable waters with no confirmation test necessary. It is the most rapid EPA approved test available with results available in only 16 hours. The read window period can also be extended through to 48 hours if necessary, minimising work over weekends.

The substrates in Colitag are chromogenic O- Nitro–Phenyl–B–D-Galactopyransoide (ONPG) and fluorogenic 4–Methyl–Umbelliferyl–B- D–Glucuronide (MUG). Coliform bacteria express the enzyme B–D–Galactosidase which metabolises ONPG to produce the yellow chromogen (O–Nitrophenol) while E. coli metabolises MUG using B–Glucuronidase to produce the fluorogen (4 – Methyl – Umbelliferone, detected using a long wave 365/366 nm U.V lamp).

Colitag also has the ability to resuscitate chlorine stressed or injured coliforms and E. coli. MUG negative E. coli (example E. coli 0157) can further be detected by the addition of Kovacs reagent to test for the production of Indole.

A 100ml sample of water is required to perform the test which can be done either qualitatively or quantitatively (MPN).

Collaborative Scientific Solutions Product List For Colitag And Accessories

Code Product Pack Size
27- 9851 Colitag Presence/Absence for 100 ml sample 100 tests
27-9851BP Colitag Presence/Absence for 100 ml sample (Blister Pack) 100 tests
27-9849 Colitag Presence/Absence for 100 ml sample 200 tests
27-9850 Colitag Presence/Absence for 100 ml sample 20 tests
27-9859 Vessels with Sodium Thiosulfate (liquid) 100/Pack
27-9859P Vessels with Sodium Thiosulfate (powder) 100/Pack
27-9855 Vessels with Sodium Thiosulfate (Flip Top) 200/Pack
27-9857 Colitag Comparator Unit