3M Petrifilm Instruction sheet

Select E. coli Count Plate
Test pour la numération sélective des E. coli
selektive E. coli (SEC) Zählplatte
Piastra per il conteggio selettivo di E. coli
Placa para recuento selectivo de E. coli
Select E. coli Telplaat
Selektiv odlingsplatta för E. coli
Select E. coli Tælleplade
Select E. coli
Selektiivinen E. coli kasvatusalusta
Selecione a Placa para Contagem de E. coli
Πλακίδιo Επιλεκτικής Καταμέτρησης E. coli
Płytka do selektywnego oznaczania liczby E. coli
Тест-пластина для подсчёта E. coli
Hızlı E. coli Sayım Plakası
大腸菌 選択用プレート（SECプレート）
选择性 大肠杆菌 测试片

 
󻺏󼹌
󻁯󼔔󺭏 󼮐󼖄󼐘󾖴󽉻󻕷󼓣󽀧
6434/6435
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Product Instructions
SEC
Select E. coli

1
(English)
EN
Issue Date: 2015-08
Product Instructions
Select E. coli Count Plate
Product Description And Intended Use
The 3M™ Petrilm™ Select E. coli Count (SEC) Plate is a sample-ready-culture medium system which contains
selective agents, nutrients, a cold-water-soluble gelling agent, and an indicator of glucuronidase activity, 5-bromo-
4-chloro-3-indolyl-D-glucuronide (BCIG), which facilitates colony enumeration. 3M Petrilm SEC Plates are used for
the enumeration of Escherichia coli (E. coli) in the food and beverage industries. Most E. coli strains are thermotolerant
and produce beta-glucuronidase, an enzyme that reacts with BCIG indicator in 3M Petrilm SEC Plates to produce
dark green to blue-green colonies. 3M Petrilm SEC Plate components are decontaminated though not sterilized. 3M
Food Safety is certied to International Organization for Standardization (ISO) 9001 for design and manufacturing. 3M
Petrilm SEC Plates have not been tested with all possible food products, food processes, testing protocols or with all
possible strains of E. coli or other bacteria.
Safety
The user should read, understand, and follow all safety information in the instructions for the 3M Petrilm SEC Plate.
Retain the safety instructions for future reference.
WARNING: Indicates a hazardous situation, which, if not avoided, could result in death or serious injury and/or
property damage.
CAUTION: Indicates a hazardous situation, which, if not avoided, could result in minor or moderate injury and/or
property damage.
WWARNING
󰄈E. coliE. coli󰄈
󰄈
atypical E. coli
󰄈

• Follow all product storage instruction contained in the instructions for use.
• Do not use beyond expiration date.

• Perform 3M Petrilm SEC Plate testing in a properly equipped laboratory under the control of a skilled
microbiologist.
• The user must train its personnel in current proper testing techniques: for example, Good Laboratory Practices1, ISO
170252, or ISO 72183.

• 3M has not documented 3M Petrilm SEC Plates for use in industries other than food and beverage. For example,
3M has not documented 3M Petrilm SEC Plates for testing water, pharmaceuticals, or cosmetics.
• Do not use 3M Petrilm SEC Plates in the diagnosis of conditions in humans or animals.
• 3M Petrilm SEC Plates do not dierentiate any one E. coli strain from another.
• High sugar content foods may decrease the color reaction of the glucuronidase and produce pale green to colorless
colonies.

• Follow current industry standards and local regulations for disposal of contaminated waste.
CAUTION
A few strains of bacteria other than E. coli, such as some Shigella, Salmonella, Enterobacter and Klebsiella, can produce
beta-glucuronidase and will produce dark green to blue-green colonies on the 3M Petrilm SEC Plate, especially when
incubated at lower than recommended temperatures4.
Consult the Safety Data Sheet for additional information.

2
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EN
If you have questions about specic applications or procedures, please visit our website at www.3M.com/foodsafety or
contact your local 3M representative or distributor.

Users are responsible for familiarizing themselves with product instructions and information. Visit our website at
, or contact your local 3M representative or distributor for more information.
When selecting a test method, it is important to recognize that external factors such as sampling methods, testing
protocols, sample preparation, handling, and laboratory technique may inuence results.
It is the user’s responsibility in selecting any test method or product to evaluate a sucient number of samples with the
appropriate matrices and microbial challenges to satisfy the user that the chosen test method meets the user’s criteria.
It is also the user’s responsibility to determine that any test methods and results meet its customers’ and suppliers’
requirements.
As with any test method, results obtained from use of any 3M Food Safety product do not constitute a guarantee of the
quality of the matrices or processes tested.

EXCEPT AS EXPRESSLY STATED IN A LIMITED WARRANTY SECTION OF INDIVIDUAL PRODUCT PACKAGING, 3M
DISCLAIMS ALL EXPRESS AND IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, ANY WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. If any 3M Food Safety Product is defective, 3M or its
authorized distributor will, at its option, replace or refund the purchase price of the product. These are your exclusive
remedies. You must promptly notify 3M within sixty days of discovery of any suspected defects in a product and return
it to 3M. Please call Customer Service (1-800-328-1671 in the U.S.) or your ocial 3M Food Safety representative for a
Returned Goods Authorization.

3M WILL NOT BE LIABLE FOR ANY LOSS OR DAMAGES, WHETHER DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES, INCLUDING BUT NOT LIMITED TO LOST PROFITS. In no event shall 3M’s liability under
any legal theory exceed the purchase price of the product alleged to be defective.

Store unopened 3M Petrilm SEC Plate pouches refrigerated or frozen at temperatures lower than or equal to 8°C
(46°F). Just prior to use, allow unopened pouches to come to room temperature before opening. Return unused 3M
Petrilm SEC Plates to pouch. Seal by folding the end of the pouch over and applying adhesive tape. 
 Store resealed pouches in a cool dry place for no longer
than four weeks. It is recommended that resealed pouches of 3M Petrilm SEC Plates be stored in a freezer (see
below) if the laboratory temperature exceeds 25°C (77°F) and/or the laboratory is located in a region where the relative
humidity exceeds 50% (with the exception of air-conditioned premises).
To store opened pouches in a freezer, place 3M Petrilm SEC Plates in a sealable container. To remove frozen 3M
Petrilm SEC Plates for use, open the container, remove the plates that are needed and immediately return remaining
plates to the freezer in the sealed container. 3M Petrilm SEC Plates should not be used past their expiration date. The
freezer that is used for open pouch storage must not have an automatic defrost cycle as this would repeatedly expose
the 3M Petrilm SEC Plates to moisture which can damage the plates.
Do not use 3M Petrilm SEC Plates that show discoloration. Expiration date and lot number are noted on each package
of 3M Petrilm SEC Plates. The lot number is also noted on individual 3M Petrilm SEC Plates.
Disposal
After use, 3M Petrilm SEC Plates may contain microorganisms that may be a potential biohazard. Follow current
industry standards for disposal.
Instructions for Use
Follow all instructions carefully. Failure to do so may lead to inaccurate results.

3
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EN

1. Use appropriate sterile diluents: Buttereld’s phosphate buered dilution water5, 0.1% peptone water5, peptone salt
diluent6, buered peptone water6, quarter-strength Ringer’s solution6, dipotassium hydrogen phosphate6, saline
solution (0.85-0.90%), bisulte-free letheen broth or distilled water.
See section “󰄈” for specic requirements.
󰄈󰄈
 If citrate buer is indicated in the standard procedure, substitute with one of the buers listed above,
warmed to 40-45°C (104-113°F).
2. Blend or homogenize sample.
3. For optimal growth and recovery of microorganisms, adjust the pH of the sample suspension to 6.5 - 7.5. For acidic
products, adjust the pH with 1N NaOH. For alkaline products, adjust the pH with 1NHCl.
Plating
1. Place the 3M Petrilm SEC Plate on a at, level surface.
2. Lift the top lm and with the pipette perpendicular to the inoculation area dispense 1 mL of sample suspension onto
the center of bottom lm.
3. Roll the top lm down onto the sample to prevent trapping air bubbles.
4. Place the 3M™ Petrilm™ Spreader with the at side down on the center of the 3M Petrilm SEC Plate. Press gently
on the center of the 3M Petrilm Spreader to distribute the sample evenly. Spread the inoculum over the entire 3M
Petrilm SEC Plate growth area before the gel is formed. Do not slide the 3M Petrilm Spreader across the lm.
5. Remove the 3M Petrilm Spreader and leave the 3M Petrilm SEC Plate undisturbed for at least one minute to
permit the gel to form.

Incubate 3M Petrilm SEC Plates in a horizontal position with the clear side up in stacks of no more than 20 plates.
Incubate 3M Petrilm SEC Plates 24 hours ± 2 hours at 42ºC ± 1ºC. Several incubation times and temperatures can
be used depending on current local reference methods, some of which are listed in the section below titled “󰄈
”.
Interpretation
1. 3M Petrilm SEC Plates can be counted using a standard colony counter or other illuminated magnier. Do not count
colonies on the foam dam since they are removed from the selective inuence of the medium. Do not count artifact
bubbles that may be present. E. coli produce dark green to light-green colonies. Colonies may have gas bubbles
associated with them. Count all green to blue-green colonies as E. coli whether there are gas bubbles present or not.
WWARNING
󰄈E. coliE. coli O157 strains are

interpreted as E. coli󰄈
2. The circular growth area is approximately 20 cm2. Estimates can be made on 3M Petrilm SEC Plates containing
greater than 150 colonies by counting the number of colonies in two or more representative squares and
determining the average number per square. Multiply the average number by 20 to determine the estimated count
per 3M Petrilm SEC Plate.
3. When colonies are present in large numbers, 3M Petrilm SEC Plates will cause the entire growth area to become
gray or blue and either or both of the following characteristics: many small, indistinct colonies and/or many gas
bubbles. When this occurs, record results as too numerous to count (TNTC). When an actual count is required, plate
at a higher dilution.
4. Where necessary, colonies may be isolated for further identication. Lift the top lm using proper testing technique
and pick the colony from the gel. Test using standard procedures.
5. If the 3M Petrilm SEC 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 negative 15°C (5°F) for
no longer than one week.
For further information refer to the “3M™ Petrilm™ Select E. coli Count Plate Interpretation Guide.” If you have
questions about specic applications or procedures, please visit our website at www.3M.com/foodsafety or contact
your local 3M representative or distributor.

4
(English)
EN
󰄈
󰄈
NF Validation certied method in compliance with ISO 161407in comparison to ISO 16649-28.
Use the following details when implementing the above Instructions for Use:

For testing all human food products, pet food and industrial environmental samples.

Use only ISO listed diluents.

Incubate 3M Petrilm SEC Plates 24 hours ± 2 hours at 42ºC ± 1ºC.
Interpretation:
Calculate the number of microorganisms present in the test sample according to ISO 72183for one plate per dilution. For
calculation, take into account only 3M Petrilm SEC Plates that contain up to 150 colonies. Estimates are outside of the
scope of the NF Validation Certication (cf. interpretation part paragraph 3).
3M 01/08 –06/01

http://nf-validation.afnor.org/en
For more information about end of validity, please refer to NF VALIDATION certicate available on the website
mentioned above.
References
1. U.S. Food and Drug Administration. Code of Federal Regulations, Title 21, Part 58. Good Laboratory Practice for
Nonclinical Laboratory Studies.
2. ISO/IEC 17025. General requirements for the competence of testing and calibration laboratories.
3. ISO 7218. Microbiology of food and animal feeding stus – General rules for microbiological examination.
4. Frampton, E.W. and L. Restaino, 1993. Methods for Escherichia coli identication in food, water and clinical samples
based on beta-glucuronidase detection. Journal of Applied Bacteriology 74, 223-233.
5. FDA. Bacteriological Analytical Manual (BAM), 8th Edition, Revision A, 1998. Reagents Index for BAM found at:
http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm055791.htm.
6. ISO 6887-1 Microbiology of food and animal feeding stus – Preparation of test samples, initial suspension and
decimal dilutions for microbiological examination.
7. ISO 16140. Microbiology of food and animals feeding stus – Protocol for the validation of alternative methods.
8. ISO 16649-2: Microbiology of food and animal feeding stus- Horizontal method for the enumeration of
ß-glucuronidase-positive Escherichia coli - Part 2: Colony- count technique at 44°C using 5-bromo-4-chloro-3-
indolyl ßD-glucuronide.
Refer to the current versions of the standard methods listed above.
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