- In 2003, the Ministry of Health, Labour and Welfare (MHLW) of Japan and, in 2001, the Japan Water Works Association (JWWA) officially approved EC Blue as one of the recognized methods for detecting Escherichia coli and Coliforms in water. EC Blue is developed based on an enzyme substrate medium method, utilizing specific enzyme substrates to detect coliform bacteria and E. coli in water.

- The rapid analysis method for E. coli and Coliforms using EC Blue from Shimadzu is an advanced solution for detecting indicator bacteria in water and food quickly and effectively. Below are the details of this method:

1. Introduction to EC Blue Rapid Test for E. coli and Coliforms

EC Blue is a microbiological testing product based on a colorimetric detection principle, enabling the rapid identification of Escherichia coli (E. coli) and Coliforms in water and food samples. This method utilizes a growth medium containing specific substrates that trigger a color reaction when the target bacteria develop.

2. Principle of Operation

2.1. Coliform Detection

- EC Blue contains the enzyme substrate β-Galactosidase, an enzyme present in all Coliform bacteria. When bacteria grow, the substrate is hydrolyzed, producing a distinctive blue color.

2.2. E. coli Detection

- In addition to β-Galactosidase, E. coli also possesses the enzyme β-Glucuronidase, which hydrolyzes a specific substrate, resulting in fluorescence under UV light (~365 nm).

3. EC Blue Testing Procedure

- Sample Preparation: take 100 mL of water sample or dilute food sample in sterile water.

- Adding EC Blue Medium: pour the EC Blue solution into the sample container or pre-prepared test bag.

- Incubation: incubate at 35-37°C for 24-28 hours.

- Result Interpretation: if the sample turns blue → positive for Coliforms. If the sample fluoresces under UV light → positive for E. coli.

4. Advantages of EC Blue Method

- Rapid Results: provides results within 24-28 hours, faster than traditional culture methods.

- Simple Process: no need for complex equipment; only an incubator and UV light are required.

- High Sensitivity: can detect as low as 1 CFU/100mL, meeting drinking water standards.

- Cost-Effective: no additional confirmation steps required, unlike the traditional MPN method.

5. Applications of EC Blue

- Testing drinking water, wastewater, swimming pool water, and food production water.

- Monitoring water quality in the food, pharmaceutical, livestock, and environmental industries.

EC Blue is an ideal method for rapid E. coli and Coliform testing in water, helping businesses and laboratories optimize microbiological testing processes.