Colitag iMPNplate-1600 water test system

The Colitag iMPNplate-1600 is claimed to be the first definitive system for measuring microbial contaminants in water with the widest testing time window: 16 to 48 h. The product features greater selectivity for total coliforms and E. coli with the help of the selective growth inhibitor of Aeromonas and Pseudomonas strains. The selective dehydrated media formula automatically resuscitates and detects chlorine-injured bacteria, resulting in a highly sensitive tool for regulated site testing.

The product is an easy-to-use device for enumerating microorganisms in a liquid sample. It is a modern approach to the traditional method of serially diluting the sample on a statistical model to produce the most probable number (MPN) index. It is US EPA approved for use in MPN format.

The time-consuming and labour-intensive process of serial tube dilutions is performed by the plate system of five duplicate wells in 10, 1 and 0.1 mL well volumes, with a 16th well for collecting the remaining sample. A mixture of a Colitag reagent satchel and 100 mL water sample is poured directly into the wells, filling all 15 wells first and the overflow well after. The plate device is manually sealed with a water-resistant film and the aid of a roller. The plate is then ready for incubation.

Result readings are direct for coliforms and definitive for E. coli with the use of a UV light source. Tests using the plate offer a high degree of sensitivity, with a detection limit ranging from 0-1600 MPN per 100 mL sample within the standard reading window. The device is stand-alone in set-up and requires simply an incubator and UV light source to perform the test.