This Fluid Thioglycollate Medium (FTM) is a dehydrated powder formulation designed for the sterility testing of turbid products, particularly in the pharmaceutical and biological industries. Unlike the standard formulation, this version does not contain agar, making it a liquid broth that is ideal for clarity and ease of observation when testing cloudy or opaque samples.
The medium provides a nutrient-rich environment for the cultivation of a wide range of microorganisms. Casein peptone (enzymatic digest) and yeast extract supply essential carbon and nitrogen sources, vitamins, and growth factors. Glucose serves as a fermentable carbohydrate to promote robust growth. Sodium chloride maintains osmotic balance.
A critical feature of this medium is the inclusion of sodium thioglycollate and L-cystine. These agents lower the oxidation-reduction (redox) potential of the medium, creating an environment that prevents the accumulation of toxic peroxides. This makes the medium suitable for the recovery of anaerobic and microaerophilic organisms, as well as aerobic bacteria. The sulfhydryl groups in these compounds also help to neutralize the inhibitory effects of heavy metal preservatives (e.g., arsenic, mercury) that may be present in the sample.
Intended Use
- Sterility testing of turbid or opaque pharmaceutical and biological products.
- Detection of aerobic bacteria in sterile products.
- Quality control in pharmaceutical, cosmetic, and medical device manufacturing.
- Environmental monitoring and research applications.
- For laboratory use only. Not for clinical diagnosis.
Composition (per Liter)
- Casein Peptone (Enzymatic Digest): 15.0 g
- Yeast Extract: 5.0 g
- Glucose: 5.0 g
- Sodium Thioglycollate: 0.5 g
- L-Cystine: 0.5 g
- Sodium Chloride: 2.5 g
- Final pH: 7.1 ± 0.2 at 25°C
Principle of the Medium
- Casein Peptone & Yeast Extract: Provide carbon, nitrogen, vitamins, and essential growth factors.
- Glucose: A fermentable carbohydrate that enhances the growth of a wide range of bacteria.
- Sodium Chloride: Maintains osmotic balance.
- Sodium Thioglycollate & L-Cystine: Lower the redox potential, preventing the accumulation of toxic peroxides and neutralizing the inhibitory effects of heavy metal preservatives.
Storage and Shelf Life
- Format: 250 g/bottle, dehydrated powder.
- Shelf Life: 3 years from date of manufacture.
- Storage: Store in a dry, dark place at 2–8°C. Keep tightly closed to prevent moisture absorption.
Q: What is Fluid Thioglycollate Medium used for?
A: It is primarily used for the sterility testing of pharmaceutical and biological products. It supports the growth of aerobic bacteria and helps to neutralize preservatives. This specific version, without agar, is ideal for testing turbid or opaque samples.
Q: What is the difference between this medium and standard FTM with agar?
A: Standard FTM often contains a small amount of agar (0.75–1.0 g/L) to help localize growth and maintain a reducing environment. This version does not contain agar, making it a clear liquid broth that is easier to observe for turbidity when testing cloudy samples.
Q: Why are thioglycollate and cystine included?
A: These compounds lower the redox potential of the medium, creating a favorable environment for bacterial growth and preventing the accumulation of toxic peroxides. They also help to neutralize the inhibitory effects of heavy metal preservatives.
Q: How should I prepare the medium?
A: Weigh 28.5 g of powder, dissolve in 1,000 mL of distilled water with heating, dispense into containers, and autoclave at 121°C for 15 minutes. Rapid cooling after autoclaving is recommended.
Q: What is the shelf life and storage condition?
A: The shelf life is 3 years from the date of manufacture when stored at 2–8°C in a dry, dark place. Keep the bottle tightly closed.
Q: Is this medium intended for clinical use?
A: No. This product is intended for laboratory quality control and sterility testing only. It is not intended for clinical diagnosis.
