Petrifilms

Germ count of liquids

The 3M Petrifilm Counting Plate Set provides a complete solution for measuring total plate count in liquids. The set is ready to use immediately and requires no special bacteriology laboratory, making measurements easy and efficient.

Set includes:

• 3M Petrifilm Counting Plates
• A single-use sterile pipette
• A sterile sample container

A spreader (reusable) is available separately. This kit allows you to easily analyze liquid samples for total germ count.

Scope

Determination of total plate count can only be performed on neutral liquids, with a pH between 6 and 8 and without residual chlorine or residual alkalinity.

Suitable samples include:

• Operating water
• Groundwater
• Tap water
• Press water or centrifuge water from laundries

How does it work?

Sampling

1. Make sure the sample tip is thoroughly clean and flushed.
2. Take a sample in the sterile sample container.

Deploying samples

1. Perform the test on a clean, draft-free workstation.
2. Place two 3M Petrifilm Counting Plates on a flat surface.
3. Aspirate 1 ml of liquid from the sample container (after gently swirling) with the sterile pipette.
4. Pipette the liquid onto the center of the 3M Petrifilm Counting Plate under the lifted cover sheet.
5. Replace the cover sheet and use the spreader to spread the liquid evenly over 20 cm².
6. Record data on the counting sheets with a waterproof marker.

Incubated

• Place the counting plates flat in an incubator.
• Stack up to 10 count plates during incubation.

Counting and results

After incubation, colonies turn red thanks to a built-in indicator. Count the red dots (Colony Forming Units, CFU) to determine the total aerobic germ count, expressed in cfu/ml.

Storing

Store the 3M Petrifilm Counting Plates in a tightly sealed container at a temperature of about 5°C. Check the expiration date on the package. If the counting plates are discolored, they are no longer usable.

Ordering Information

The 3M Petrifilm Counting Plates are available:

• Per duplicate measurement
• Per set for 25 duplo provisions

The set includes the counting plates, sterile pipettes and sample jars. Spreaders can be ordered separately.

Other fluid analysis

In addition to Petrifilms for total germ count determination, CCD also offers Petrifilms for count determination:

• Fungi and yeasts
• E. coli(Escherichia coli)

These Petrifilm counting plates are available to order. Please consider delivery times, minimum order quantities and specific incubation conditions.

With the 3M Petrifilm Counting Plate Set, you can easily perform reliable analyses, ensuring hygiene in liquids.