3M Petrifilm 6402 Instrucciones Del Producto página 4

2. Examine 3M Petrifilm RCC Plates for coliform growth at any time during a 24 hours ± 2 hours incubation interval depending on the desired
information and method being followed (described below*). See section,"Specific Instructions for Validated Methods" for specific requirements.
Because coliform growth is affected by temperature, time out of the incubator should be minimized to avoid extending the detection time.
Interpretation and Enumeration
For interpretation see section "Specific Instructions for Validated Methods"
1. Indirect back lighting may enhance early detection of yellow acid zones on 3M Petrifilm RCC Plates. Coliform colonies may begin to appear at 6
hours of incubation as discrete yellow zones indicating colony forming units (CFUs) (see Figure E). Continue incubating 3M Petrifilm RCC Plates
to detect additional acid zones and/or red colonies associated with acid. Do not count colonies on the foam dam since they are removed from the
selective influence of the medium. Do not count artifact bubbles that may be present.
Some coliforms produce large amounts of acid. For these organisms, fusion of the yellow acid zones could occur at about 20 colonies per plate.
The circular growth area is approximately 20 cm². Estimates can be made on 3M Petrifilm RCC Plates containing greater than 50 acid zones by
counting the number of acid zones in one or more representative squares and determining the average number per square. Multiply the average
number by 20 to determine total count per 3M Petrifilm RCC Plate.
2. Where necessary, colonies may be isolated for further identification. Lift the top film and pick the colony from the gel (see Figure H). Test using
standard procedures.
3. If the 3M Petrifilm RCC Plates cannot be counted within 1 hour of removal from the incubator, they may be stored for later enumeration by freezing
in a sealable container at temperatures lower than or equal to minus 15°C (5°F) for no longer than one week.
For further information refer to the 3M™ Petrifilm™ Rapid Coliform Count Plate "Interpretation Guide." If you have questions about specific
applications or procedures, please visit our website at www.3M.com/foodsafety or contact your local 3M representative or distributor.
Specific Instructions for Validated Methods
AOAC® Official Methods 2000.15: Dry Rehydratable Film Method for the Rapid Enumeration of coliform in Foods.
SM
Incubate 3M Petrifilm RCC Plates up to 24 hours ± 2 hours at 35ºC ± 1ºC.
NF Validation by AFNOR Certification:
NF Validation certified method in compliance with ISO 16140
Scope of the validation: All human food products.
Use the following details when implementing the above Instructions for Use:
Sample preparation:
Use only ISO listed diluents .
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Incubation:
For processed pork products and seafood incubate 3M Petrifilm RCC Plates 14 hours ± 30 minutes at 30ºC ± 1ºC.
For all other foods incubate 3M Petrifilm RCC Plates 14 hours ± 30 minutes at 35ºC ± 1ºC.
Interpretation:
Calculate the number of microorganisms present in the test sample according to ISO 7218
scope of the ISO 16140 validation.
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NF Validation certified method in compliance with ISO 16140
Scope of the validation: All human food products.
Use the following details when implementing the above Instructions for Use:
Sample preparation:
Use only ISO listed diluents.
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Incubation:
For processed pork products and seafood incubate 3M Petrifilm RCC Plates 24 hours ± 2 hours at 30ºC ± 1ºC.
For all other foods incubate 3M Petrifilm RCC Plates 24 hours ± 2 hours at 35ºC ± 1ºC.
Interpretation:
Calculate the number of microorganisms present in the test sample according to ISO 7218
Estimates are outside of the scope of the ISO 16140
in comparison to ISO 4832
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in comparison to ISO 4832
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validation.
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(3M-01/5-03/97 A).
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for one plate per dilution. Estimates are outside of the
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(3M-01/5-03/97 B).
1
for one plate per dilution.
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