Division 2 Treatment of samples

The organs and tissues listed in paragraph 1 may be pooled, but separate treatment of faecal material is essential. Swabs should be placed in sufficient antibiotic medium to ensure full immersion. Faeces samples and organs should be homogenized (in an enclosed blender or using a pestle and mortar and sterile sand) in antibiotic medium and made to 10-20 % w/v suspensions in the medium. The suspensions should be left for about two hours at ambient temperature (or longer periods at 4 °C) and then clarified by centrifugation (e.g. 800 to 1 000 g for 10 minutes).