In a sterility test, how long are samples incubated in growth medium?

In sterility testing, samples are typically incubated in growth medium for a duration of 14 days. This period is established to ensure that any viable microorganisms present in the samples have sufficient time to grow and be detected. Incubating for 14 days allows for the identification of a wide range of potential contaminants, ensuring a thorough assessment of sterility.

The choice of 14 days strikes a balance, allowing common contaminants to multiply while minimizing the risk of false negatives that could occur if the incubation period were shorter. Additionally, this time frame aligns with industry standards for sterility testing as outlined in the relevant compounding regulations.

While other durations may seem reasonable, they either do not provide enough time to reliably detect potential contaminants or exceed the practical requirements for sterility assurance in the context of compounding sterile preparations.