Tissue Testing Services

Bioburden Tissue Testing

Routine testing of tissue should be performed to prove that tissue processing is in control. The appropriate frequency and number of samples depend upon many factors including the sterility assurance level, product types, sterilization type, environmental control, and the manufacturing process control.

The Bioburden test for tissue determines the total number of viable aerobic bacterial, mold, and yeasts in or on a tissue product or solution. It is performed on any tissue product that requires control of bioburden counts, usually as part of a sterilization program. This test can be used as an early warning system for potential production problems that may lead to inadequate sterilization or disinfection processing and to calculate the necessary dose for effective radiation sterilization.

Testing Types

The four most common types of bioburden tests are Aerobic Count, Anaerobic Count, Fungi/ Mold Count, And Spore Count. In additon, Recovery Efficiency Test and Most Probable Number test is also need in some cases.

• Aerobic Count

For aerobic count test, this test enumerates the overall level of microorganisms that exist in an aerobic environment, typically most bacteria, fungi/mold, and yeast, this test usually run for all bioburden determinations, with other selective tests added to supplement the data.

• Anaerobic Count

For anaerobic count test, it selects for anaerobic organisms by growing them in an anaerobic environment. It’s typically performed when a product has a biologic component.

• Fungi/ Mold Count

For fungi/mold count test, this selects for most fungi and yeast by inhibiting the growth of bacteria. It typically performed in conjunction with the aerobic count as an indication of the microbial load for these two most common categories.

• Spore Count

For the spore count test, it selects for bacterial spores by eliminating other bacterial cells using heat. Typically run in conjunction with aerobic count to determine the percent of spores in a microbial population, which can be a significant factor in sterilization validation.

• Recovery Efficiency Test

A Recovery Efficiency Test is required to be performed to validate a bioburden test. Exhaustive recovery and product inoculation are two general approaches for conducting a recovery efficiency test. We recommended a recovery efficiency should be assessed before the start of the bioburden test, then validating the recovery efficiency and applying this to future testing.

• Most Probable Number Test

For tissue products with low bioburden, the Most Probable Number test may be utilized. This test immerses the product directly in nutritive media and following a 7d incubation, evaluating the media for growth situation.

Applicable Standards

Both the EO Sterilization standard (ISO 11135) and the Radiation Sterilization standards (ISO 11137-1, ISO 11137-2) give out guidance for conducting the Bioburden test for tissue.

STEMart offers Bioburden Tissue Testing Services following the Radiation Sterilization standards (ANSI/AAMI/ISO 11137-1 & 2) and the EO Sterilization standard (ANSI/AAMI/ISO 11135).

If you have additional questions about Tissue Testing Services or would like to find out more about our services, please feel free to contact us.