General procedures at the lab

Colonies of bacterium causing mastitis

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.

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