Sterility Testing

Sterility Culture Media

Merck offers the following sterility culture media:


Soybean-Casein Digest Medium (Trypcase Soy Broth)
The Soybean-Casein Digest Medium, also known as Trypcase Soy Broth, is suitable for the culture of both fungi and aerobic bacteria. This medium is used for sterility testing by membrane filtration or by direct inoculation. It is also used as pre-enrichment broth for non sterile products. Compliant to the USP, EP and JP.

Fluid Thioglycollate Medium
Fluid Thioglycollate Medium (FTM) is primarily intended for the detection of anaerobic bacteria. However, it also enables aerobic bacterial detection. This medium is used for sterility testing by membrane filtration or direct inoculation as described in the USP, EP and JP.

Clear Thioglycollate Medium
Clear Thioglycollate Medium has the same growth promotion properties as the standard FTM and is compliant to the USP, EP and JP. The alternative formulation brings extra visual clarity versus the FTM which has a slight turbidity or haze. A high visual clarity medium is preferred by many users, when compared with the hazy or opalescent appearance of FTM.

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Rinsing Fluids for Sterility Testing

Fluid A
Suitable as a general rinse buffer, and compatible with most samples. Excellent for dissolving or diluting samples, reconstituting commercial microorganisms, or as a transport medium for microorganisms.

Fluid D
Suitable for testing samples that contain lecithin or oil, and compatible with most antibiotics. Excellent for rinsing sterile pathways of devices, and typically needed for rinse method testing of medical devices.

Fluid K
Suitable for testing samples that contain petrolatum, oils, or oily solutions. Excellent for rinsing pathways of medical devices, and for samples that are “difficult” to filter or dissolve.

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Double Packed Sterility Media & Rinse Fluids for Increased Test Method Reliability

Trypcase Soy Broth (Soybean-Casein Digest Medium), Fluid Thioglycollate Medium, Clear Thioglycollate Medium, and USP Rinse Fluid A are also available in double packed format.

The sterilized double Tyvek® packaging allows to streamline the cleaning procedures, to minimize the risk of cross-contamination in laminar flow hoods and to secure an efficient decontamination of isolator chambers. The products are supplied as 100 mL bottles, screw cap with septum closure.

The sterilization efficiency of the packaging including the space between the protective cap and the septum is verified on each batch with biological indicators.

Ordering Information

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