5. COLLECTION OF SAMPLES

See Appendix B of Volume 2.

6. MATERIALS AND SPECIAL EQUIPMENT

The media listed below (items 3-5) are commercially available and are to be prepared and sterilized according to the manufacture's instructions.

1) HGMF (1600 grid-cell, 0.45 µm pore size; available as ISO-GRID Membrane Filters from Oxoid Ltd., Nepean, Ont.) or equivalent

2) Membrane filter forceps

3) Peptone water, 0.1% (PW) or Peptone/Tween 80 diluent (PT) (if spreadfilter is to be used)

4) Nutrient agar (NA) plates, if a resuscitation step is required

5) m-FC agar plates (without rosolic acid)

6) Enzyme solutions (Appendix E of Volume 2; 9. 6) as required for some food products

7) Stomacher or equivalent

8) Stomacher bags (commercially available) with interior filter or pipet-tip prefilters (Filtaflex Ltd., Almonte, Ont.)

8) Spreadfilter with funnel (Filtaflex) or ISO-GRID filtration unit (Oxoid) or equivalent

9) Incubators capable of maintaining 35 ^oC

Note: It is the responsibility of each laboratory to ensure that the temperature of the incubators or water baths are maintained at the recommended temperatures. Where 35^oC is recommended in the text of the method, the incubator may be at 35 +/-1.0^o C. Similarly, lower temperatures of 30 or 25 may be +/- 1.0^oC. However, where higher temperatures are recommended, such as 43 or 45.5^oC, it is imperative that the incubators or water baths be maintained within 0.5^oC due to potential lethality of higher temperatures on the microorganism being isolated.

Optional

11) Manual or automated colony counting devices

7. PROCEDURE

Analyze each sample unit individually.

Carry out the test in accordance with the following instructions:

7.1 Handling of Sample Units