General procedures at the lab
Once the milk sample arrives at the laboratory, a minimum of 48 hours is required to process it. The sample is plated onto general-purpose culture media and selective culture media for the main aetiological groups.
- When analysing individual samples, 10-20 microlitres of milk are streaked out on the plate. It is important to get single colonies, so the milk must be streaked out well, in 3 separate streaks.
- In the case of bulk milk tank samples, cultures are prepared with 0.2 mL of the sample, 0.2 mL of a 1:5 dilution of milk with a sterile solution and 0.2 mL of a 1:50 dilution.
All samples are incubated at 37 °C and read at 24 and 48 hours.