Colifast - Field Kit

Three methods are available with the kit:

• The Rapid method
• Presence/absence
• Quantitative (MPN)

The main method of the kit is a rapid method that provides an answer as early as 75 minutes, 2 hours at the latest (limited to levels above 500 cfu/100ml). In addition, the kit includes methods for a quantitative MPN (Most Probable Number) method and presence/absence results. The procedure is very easy to perform, and requires no laboratory skills. Colifast Field Kit is delivered in a robust and portable metal case, and all equipment required for the water analysis is included. The Colifast Micro Detector (CMD) is used in combination with a growth medium for specific detection of target bacteria. Combined, they provide a simple  analysis and rapid results that quantify the amount of coliform and thermotolerant bacteria in water. The method is based upon the patented technology of Colifast AS.

• Spreadsheet for calculating the bacterial concentrations when conducting the Rapid method.
• WebTool for calculating bacterial concentrations when using the rapid method

Method

The Colifast technology is based on a chemical reaction between a substrate in the growth medium and enzymes produced by the coliform bacteria. The bacterial enzyme β-D-galactosidase hydrolyses the substrate 4-methylumbelliferyl-β-D-galactoside, which results in the release of the fluorescent product 4-methylumbelliferone (MU). In addition to substrate, activators and growth factors, the medium comprises inhibitors that prevent the growth of non-coliform bacteria. The results are measured in fluorescent units. An increase in the number of bacteria corresponds to an increased amount of β-D-galactosidase (enzyme). The subsequent increase in the amount of MU (fluorescent product) results in a higher value on the instrument (Colifast Micro Detector). The incubation temperature selects for thermotolerant coliforms at 44 °C and total coliforms at 37 °C.