Well Water Test Kit Product Documents and Resources

Optional UV Flashlight: Our growth medium is designed and tested to deliver reliable, accurate results for E. coli detection in 100mL water samples. For users who have positive test results in ambient light for E. coli and who would like additional verification, we offer this optional confirmation procedure: shine a UV light (365nm) on the sample. If it does fluoresce blue, this increases the likelihood the sample is positive for E. coli. This step is not required and does not indicate any concern with the primary test results. It simply provides independent corroboration for those seeking extra assurance.

Why a Yellow/Yellow Brown Sample in Daylight Might be Positive for Total Coliforms Under UV Light: Total Coliforms are a large group of different types of bacteria, many of which are not of fecal origin. Fecal bacteria and pathogens in drinking water are what can potentially make people and animals sick. E. coli is
both a fecal bacteria and Total Coliform, but not all Total Coliforms are E. coli. Total Coliforms only give a general indication of the sanitary condition of a water supply.
E. coli is the most specific indicator of fecal bacteria and pathogens in water, which is why the U.S. EPA specifies it in national drinking water standards.