N.33 – Correct aseptic sampling during air sampling monitoring


The correct sampling  is fundamental to avoid a microbial contamination with possible wrong results at the end of the analytical process.

It is for this reason that all the staff involved in the sampling process should be trained.

We are reporting some Guide Lines that should be distributed and explained to all involved personnel.

-Guide Lines


• Contaminate the plate touching the inside surfaces

• Contaminate the inside edge of the lid of the container

• Lean the lid of the plate on a contaminated surface during the sampling operation

• Collect a unrepresentative sample

• Use damaged or contaminated containers


• Wash the hands and / or wear clean and sterile gloves

• Label / identify the plate before to start the sampling operation

• Eliminate the gloves and wash the hands at the end of sampling operation

• The plate should be removed from its protective bag only for labelling and sampling.

-Sample Identification

The plate should be identified before to start the sampling process with the following data:

  • reference number or letter
  • operator’s name
  • name or type of sample
  • site of sampling
  • exact point of sampling
  • date and hour of sampling
  • sample temperature at time of sampling
  • expected temperature during transit
  • store the sample at the correct temperature as indicated in the sampling plan document (e.g.: 4°C).

-Sampling delivery

The container with the sample should be stored in dark, insulated box and delivered to the analytical laboratory not later than 4-6 hours.

-Temperature during transit

The samples for microbiological tests should be stored at 4°C to avoid the multiplication of the microbial population, with the purpose to avoid wrong analytical results.

This goal is reached using portable, battery operated refrigerators.