How to enumerate the microorganisms in a food sample using Dilucup?

  1. First homogenize the sample if it is solid. This is the first 1/10 dilution.
  2. Once the sample is suspended or if the sample is liquid, serial dilute it using Dilucup.
  3. Plate 1 mL of the selected suspension(s) and incubate.
  4. Count the colonies (the plates should have between 30 and 300 CFUs to get a statistically valid result).
  5. Divide the average number of CFUs per the dilution level to get the number of microorganisms per mL or g in the original sample.

Watch the video to understand it better!