What are the recommended storage conditions?
Store at 2–30°C and away from light. What is the Colilert comparator?
The Colilert comparator is a liquid colour and fluorescence reference. Its purpose is to assist in distinguishing a minimal positive from a negative test result. How do you use the Colilert comparator?
At 24–28 hours, any yellow colour or fluorescence equal to or greater than the comparator is considered a positive test result. What should the colour and consistency of the Colilert 250 reagent powder be?
The Colilert 250 reagent powder should be should be white to off-white in colour; it should be dry and free-flowing. Any concerns about the colour or integrity of the powder should be directed to IDEXX Technical Support
. Can Colilert 250 samples be read after 24 hours?
Yes, if they are negative. If an inoculated Colilert 250 Test sample is inadvertently incubated over 28 hours, lack of yellow colour is a valid negative test; a yellow colour after the 28 hours is not valid and should be repeated or verified. Can Colilert 250 samples be read before 24 hours?
Yes, if they are positive. An inoculated Colilert 250 sample that is positive for coliforms and E. coli
before 24 hours is a valid positive test for both coliforms and E. coli.
If the sample is positive before 24 hours for coliforms only, the sample is a valid positive test for coliforms. However, the sample should be incubated for a longer period (up to 24 hours, but not greater than 28 hours total time) to determine whether E. coli