In the world of pharmaceuticals and medical devices, ensuring products are free from harmful bacteria and mold is paramount to patient safety. This is where sterility testing comes into play. In this article, we delve into why sterility testing is crucial, the meticulous processes involved, and how Infinity Laboratories ensures the highest standards of safety for its clients’ products.


Why Sterility Testing Matters

Pharmaceuticals and medical devices intended for use inside the human body bypass natural defense mechanisms like the skin and stomach acid. If these products contain bacteria or mold, they can cause serious harm, ranging from infections to potentially life-threatening complications. Sterility testing is the means by which we ensure these products are devoid of microbial contamination, safeguarding patient health.


The Basics of Sterility Testing at Infinity Laboratories


Where: Cleanrooms and Laminar Flow Hoods

At Infinity Laboratories, sterility testing takes place in rigorously controlled environments called cleanrooms. These rooms adhere to ISO 7 specifications, maintaining air cleanliness by cycling air through HEPA filters 30-60 times per hour. Regular sporicidal and antibacterial cleanings are conducted to maintain sterility, with environmental monitoring ensuring no compromise to the testing environment.

Personnel entering the cleanroom undergo thorough gowning procedures, ensuring no exposed skin. Gamma-irradiated gowning materials further enhance sterility. Testing is conducted within Laminar Flow Hoods, meeting ISO 5 specifications to minimize airborne particles and maintain a sterile environment.


What: Media and Canisters

Sterility testing utilizes Soybean-Casein Digest Medium and Fluid Thioglycollate Medium for incubation, catering to aerobic and anaerobic bacterial growth, respectively. Canisters equipped with 0.45-micron cellulose acetate filters facilitate sample filtration, retaining active ingredients while removing potential contaminants.


How: Pumps and Incubation

Before testing, method suitability evaluations determine the most appropriate conditions for microbial growth. Closed system testing prevents exposure to external contaminants, with vacuum manipulation facilitating sample processing within canisters.

Incubation occurs over 14 days, with regular checks for microbial growth. Turbidity in samples prompts further testing, with plating on TSA plates for identification and incubation under varied conditions. Any growth indicates a failed test, ensuring only sterile products reach the market.



Sterility testing is crucial for ensuring pharmaceutical and medical device safety. Infinity Laboratories employs stringent protocols and state-of-the-art facilities to conduct thorough sterility testing, safeguarding patient well-being. With a commitment to quality and safety, Infinity Laboratories stands as a trusted partner in the success of pharmaceutical and medical device manufacturers.


About Infinity Laboratories

Infinity Laboratories is an FDA Registered, ISO 17025 Accredited, and DEA licensed network of testing facilities specializing in chemical and microbiological sciences. Committed to excellence, Infinity Laboratories goes beyond testing to support the success of its clients.


About the Authors

Luke Miller, Ph.D., serves as the Chief Operating Officer of Infinity Laboratories, bringing expertise and leadership to the organization.

Nadia Miller contributed as a Microbiology Analyst, ensuring meticulous attention to detail in sterility testing procedures.