Bioburden /Bioburden Validation

Bioburden is a microbiological test aiming to determine the population of microorganisms on a raw material, product component or finished medical device just prior to sterilization.

It is used to establish parameters for an effective sterilization process and verify that the bioburden level remains consistent over time. A significant increase in the device bioburden would reduce the sterility assurance level of the sterilization process.

Before performing routine bioburden, the suitability of the method should be demonstrated.

The purpose of this suitability test (bioburden validation) is to:

Ensure effective recovery of microorganisms and determine a recovery factor (percentage of microorganisms not removed from the device)

Ensure that the test method does not inhibit or activate growth of the recovered microorganisms.

Validate culture media and incubation conditions.

If any changes affecting materials, assembly or configuration are made to the product, the bioburden method should be revalidated.

Bioburden tests may include aerobic bacteria, aerobic fungi (yeasts and molds), and anaerobes. Many factors enter into the choice of the type of tests most appropriate for your product. Generally, the test is performed for aerobic bacteria and fungi.

Bioburden and bioburden suitability tests are part of our scope of accreditation

Applied standard:

ISO 11737-1:

Method Process:


Bioburden Validation

Protocol generation and validation

• Recovery efficiency

• Bactericidal & fungicidal effect

• Incubation conditions & culture media


Sample is aseptically transferred to an appropriate volume of extraction fluid and then mechanically agitated to remove microorganisms

Test method

• Membrane filtration

• Plate count

•Most Probable Number


Total count with a breakdown of bacteria and fungi

Sampling requirements:

Samples needs to be representative of the process and should include all manufacturing steps’.

Samples may be obtained from rejected materials if those materials have been subjected to the same processing conditions.