What are the two general methods to perform a sterility test?

What are the two general methods to perform a sterility test?

• A. Direct transfer (DT)/direct inoculation method; membrane filtration method (MF)
• B. Direct inoculation and filtration
• C. Aseptic transfer and filtration
• D. Direct inoculation and membrane filtration (MF) only

Answer: (C)

In sterility testing, there are two standard approaches to detect contaminants: direct inoculation into culture media and membrane filtration. Direct inoculation means taking the sample and directly inoculating it into appropriate growth media to see if any microorganisms grow. Membrane filtration involves filtering a defined volume of the sample through a sterile membrane; the membrane is then incubated in culture media to detect any retained microorganisms. Aseptic transfer is a critical technique to prevent contamination during sample handling, but it’s not a separate testing method. It supports both approaches rather than defining a distinct method itself. So the correct pairing is direct inoculation and membrane filtration, since these are the two general methods used for sterility testing.

In sterility testing, there are two standard approaches to detect contaminants: direct inoculation into culture media and membrane filtration.

Direct inoculation means taking the sample and directly inoculating it into appropriate growth media to see if any microorganisms grow. Membrane filtration involves filtering a defined volume of the sample through a sterile membrane; the membrane is then incubated in culture media to detect any retained microorganisms.

Aseptic transfer is a critical technique to prevent contamination during sample handling, but it’s not a separate testing method. It supports both approaches rather than defining a distinct method itself.

So the correct pairing is direct inoculation and membrane filtration, since these are the two general methods used for sterility testing.