Pink color in the medium is caused by resazurin, which indicates oxygen exposure. In oxygen-free conditions, it remains colorless or very pale. When oxygen enters, it turns pink, usually at the surface. A thin pink layer is normal, but pink color extending deeper into the medium may indicate excessive oxygen exposure and it affects anaerobic microorganism recovery. In such cases, the medium should be evaluated against the established acceptance criteria before use.
When should you use Fluid Thioglycollate Medium instead of TSB or other culture media?
Use Fluid Thioglycollate Medium (FTM) when the test requires the detection and recovery of anaerobic or oxygen-sensitive microorganisms, especially during sterility testing and pharmaceutical quality control as FTM provides a low-oxygen environment that supports the growth of anaerobic organisms. Tryptic Soy Broth (TSB) is generally preferred for aerobic and facultative microorganisms. However, when broad microbial recovery is needed, using FTM together with TSB can help detect a wider range of microorganisms.
How long can prepared Fluid Thioglycollate Medium (FTM) can be stored?
Prepared FTM should be stored only for the validated period specified by the laboratory or manufacturer. It should be prepared according to the manufacturer’s instructions, sterilised using a validated autoclave cycle, and stored properly in sealed containers under the recommended conditions, away from excessive heat and light. Before use, check for excessive pink coloration, contamination, or other signs of deterioration.
What is Thioglycollate Medium USP used for?
Thioglycollate Medium USP is a liquid medium supporting growth of aerobic, anaerobic, and microaerophilic bacteria. Not just for sterility testing - also used for: (1) Cultivation of anaerobes without anaerobic chamber, (2) Determination of oxygen requirements of bacteria, (3) Maintenance of stock cultures, (4) Starting cultures for anaerobic studies, (5) Clostridium enrichment. Contains thioglycollate and cystine as reducing agents creating anaerobic environment in lower tube portions. Resazurin indicator shows oxygen presence (pink) or absence (colorless). Heat to drive off oxygen before use if >1/3 is pink.
Fluid Thioglycollate Medium (FTM) is recommended for the cultivation and recovery of aerobic, anaerobic, and microaerophilic microorganisms. It is typically incubated at 30–35°C for up to 3 days, as applicable to the test method. Representative microorganisms include Bacillus spizizenii, Staphylococcus aureus, Pseudomonas aeruginosa, and the anaerobe Clostridium sporogenes. FTM can also support the growth of fungi, such as Candida albicans and Aspergillus brasiliensis, when its use has been validated at 20–25°C. Therefore, FTM is particularly suitable for sterility testing, where recovery of different types of microorganisms is required.
Why is my Fluid Thioglycollate Medium (FTM) not supporting Anerobic growth?
If Fluid Thioglycollate Medium (FTM) does not support anaerobic growth, the issue may be due to excess oxygen exposure, incorrect preparation or pH, overheating during sterilization, improper storage, or expired media. Extensive pink coloration may indicate oxidation. The condition and handling of the anaerobic microorganism can also affect growth. To ensure proper performance, prepare and store the medium as recommended, minimize oxygen exposure, and perform Growth Promotion Testing (GPT) as required.
What's the difference between ready-to-use and dehydrated FTM?
Ready-to-use (RTU) Fluid Thioglycollate Medium (FTM) is supplied as a prepared and quality-controlled medium that can be used directly after receiving and inspecting it. It saves preparation time, reduces handling errors, and supports consistent performance. Dehydrated FTM is supplied as a powder that must be reconstituted with purified water and sterilized before use. It provides greater flexibility in batch size and preparation. The choice between RTU and dehydrated FTM depends on the laboratory’s workload, resources, requirements, and validation needs.
How should I interpret different growth patterns in FTM tubes?
Different growth patterns in Fluid Thioglycollate Medium (FTM) indicate the microorganism’s oxygen requirements. Obligate aerobes grow mainly near the surface, while obligate anaerobes grow at the bottom. Facultative anaerobes grow throughout the medium, often more densely near the top. Microaerophiles usually grow in a narrow band below the surface. These patterns provide preliminary information and should be confirmed using appropriate identification tests.
Which USP requirements apply to Fluid Thioglycollate Medium (FTM) in Sterility Testing?
USP <71> recommends Fluid Thioglycollate Medium (FTM) for detecting aerobic and anaerobic bacteria during sterility testing. FTM may also support the growth of aerobes, anaerobes, and fungi instead of SCDM, provided its suitability is validated through appropriate Growth Promotion Testing (GPT). Each batch should demonstrate recovery of specified microorganisms from a low-level inoculum under validated conditions. The medium’s appearance, pH, and storage conditions should meet established specifications. Laboratories should follow validated procedures, required incubation conditions, and appropriate aseptic techniques throughout testing.
What is Fluid Thioglycollate Medium used for?
FTM is used for Sterility testing in pharmaceutical industries to check for aerobic and anaerobic contamination in biologicals, vaccines, and injectables (in compliance with applicable pharmacopeial standards like USP Chapter <71>). Its reducing environment supports the recovery of anaerobic, aerobic, and facultative anaerobic microorganisms, including oxygen-sensitive contaminants. FTM is also useful for testing certain preservative-containing products
Suspend 29.75 g in 1000 mL of purified or distilled water. Heat to boiling with constant mixing until the medium dissolves completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Avoid overheating or prolonged autoclaving, as caramelization of dextrose may reduce its capacity to maintain low oxygen levels and may result in the formation of toxic oxidative breakdown products from the medium components. Cool to 25°C and store in a cool, dark place, preferably below 25°C.
Note: If more than the upper one-third of the medium develops a pink-purple colour, it may be restored once by heating in a water bath or free-flowing steam until the pink-purple colour disappears.
Why is sterility testing important in pharmaceuticals?
Sterility testing is important in pharmaceuticals because it helps confirm that products like vaccines, injectibles, medical implants, etc. intended to be sterile are completely free from viable microorganisms and safe for patient use. It supports quality control and regulatory compliance by helping verify effective sterilization and aseptic manufacturing processes. Reliable sterility testing also helps detect microbial contamination before products reach patients, thus reducing the risk of infections, product recalls, and regulatory issues.
Where can I find the Technical Data Sheet for this product?
All technical documentation, including TDS, SDS, and COA, is available on our localized US portal. - Visit [www.himedialabs.com/us](https://www.himedialabs.com/us). - Search for your specific product code (e.g., M009 for the standard USP formulation). - High-volume users can also request bulk-batch COAs directly from our Pennsylvania-based support team. - For Technical & Product Support: Email: infous@himedialabs.com
What are the safety precautions for using Fluid Thioglycollate Medium?
When using Fluid Thioglycollate Medium (FTM), follow the manufacturer’s instructions for preparation, sterilization, storage, and handling, as provided in the Technical Datasheet (TD), Electronic Instructions for Use (eIFU), and Safety Data Sheet (SDS). Use aseptic techniques to prevent contamination and wear appropriate personal protective equipment (PPE), including gloves, a lab coat, and eye protection. Before use, inspect the medium for excessive pink coloration or other signs of deterioration. Do not use expired or unsuitable media, and dispose of used FTM in accordance with applicable biosafety and waste-disposal procedures.
What is the difference between standard FTM and HiVeg™ Fluid Thioglycollate Medium?
Standard FTM may contain animal-derived peptones, depending on its formulation, whereas HiVeg® Fluid Thioglycollate Medium uses plant-based ingredients as an alternative to animal-derived components. This makes HiVeg® FTM suitable for laboratories seeking animal-origin-free (AOF) media and helps address concerns related to BSE/TSE risks. Both are designed to meet applicable performance requirements for sterility testing, complying with applicable pharmacopeial standards like USP Chapter <71>
Plot No. C40, Road No. 21Y, MIDC, Wagle Industrial Estate, Thane(W)-400604, MH, India
