Bioburden Testing for Medical Devices
Bioburden testing is one method of many used in medical device sterilization testing processes. Learn more about this important method, who needs it, and how it works.
What is a bioburden test?
A bioburden test is an important part of the medical device sterilization process and adheres to international standards and regulatory requirements for market approval and patient safety.
Bioburden testing is a laboratory procedure that measures the number of viable microorganisms on the device’s surface to provide a baseline microbial count before the device undergoes sterilization. This is necessary to ensure the sterilization method effectively reduces the microbial load to safe levels.
Who needs a bioburden test?
Medical device manufacturers use bioburden testing to confirm that their products are safe for use and meet regulatory standards. Sterilization service providers also use bioburden testing to help set sterilization parameters.
How does the bioburden test work?
Bioburden testing requires aseptic techniques, controls, conducting replicates, and validation. There are seven primary steps to performing bioburden testing:
Sample collection
Representative samples of the medical device must be tested. The sample size should reflect the typical manufacturing process and potential contamination risks.
Preparation
The test must be performed in a controlled environment to prevent external contamination. For devices with complex geometries or surfaces, rinsing or swabbing methods may be used to collect microorganisms.
Extraction
There are two microorganism collection methods: Rinsing method and swabbing method.
Microbial enumeration steps
Filtration: The extraction fluid is passed through a membrane filter that traps microorganisms.
Plating: The membrane filter or aliquots of the extraction fluid are plated onto nutrient agar plates.
Incubation: The agar plates are incubated under temperature and duration conditions suitable for microorganism growth.
Counting colonies
After incubation, the number of colonies on the agar plates are counted.
Calculation
Dilution factors, extraction fluid volume, and the area of the device sampled are used to calculate the total bioburden.
Documentation and reporting
Test data is recorded, results are analyzed to determine if bioburden levels are within acceptable limits, and a detailed report is prepared documenting the procedure, results, and conclusions. The report is necessary for regulatory submissions and quality assurance.
What standards apply?
Medical device bioburden testing is required to meet regulations in the United States. Medical device manufacturers must perform bioburden testing as part of the process validation for sterilization methods and is outlined in several FDA guidelines and standards, including ISO 11737-1.
Why LSO?
As an FDA-registered and ISO 13485-certified contract manufacturing organization, Life Science Outsourcing (LSO) offers assembly, packaging, sterilization, and specialized capabilities in diagnostics packaging and design. Our unique business model combines comprehensive in-house services and extensive regulatory expertise, allowing us to provide the agility and flexibility needed to expedite market launches while standardizing the supply chain and minimizing risks.
