Fluid thioglycollate medium

Media-hlled vials (soybean casein digest broth or fluid thioglycollate medium) are hlled on the hlling line, transported to the freeze drier, loaded into the chamber, subjected to a simulated lyophilization process, stoppered, sealed, and incubated for 14 days at 25°C. The minimum number of vials to be used is 5000. 

An anaerobic condition exists if there is need for sterile inert gas to break the vacuum on the chamber and remain in the container after sealing. The use of anaerobic medium (e.g., alternative fluid thioglycolate medium) would be appropriate where the presence of anaerobic organisms has been confirmed in either environmental monitoring or, more likely, during end product sterility testing. 

Medium Fluid Thioglycolate medium filled in 3-ml glass vials Physical appearance Very light amber, clear solution PH ... 

Fluid thioglycolate medium for detection of anaerobic growth... 

In the membrane filtration method, the product samples are put aseptically into a volume of non-inhibitory diluent and then passed through a sterile 0.45 pm membrane filter (Fig. 1). The membrane is rinsed through with additional volumes of diluent, then aseptically cut in half. Half is transferred to a container of soybean casein digest medium (SCDM) and the other to fluid thioglycollate medium (FTM). 

Sterility tests are normally performed by incubating the sample with fluid thioglycollate medium at 30-35° C for 14 days or with soybean-casein digest medium at 20-25° C for 14 days. The sample volume should be as large as that for human dosage. If bacterial growth is observed in either test, the preparation is considered asterile. For PET radiopharmaceuticals, these tests must be started within 24 h after the release of the product. 

The technique of membrane filtration is used whenever the nature of the product permits. The membrane is transferred to the growth medium, or the medium is transferred onto the membrane. Alternatively, the prepared sample is inoculated directly into the appropriate media. This method is only used when the product (e.g. some vaccines) cannot be dissolved or diluted in a nontoxic diluent. The media used are fluid thioglycolate medium (FTM) for aerobic, micro-aerophilic and anaerobic bacteria, and Soybean casein digest broth (SCDB) for aerobic bacteria and fungi. FTM and SCDB are incubated at 30-35 °C and 20-25 °C respectively, both for a period of not less than 14 days. This relatively long incubation period seems to be justified, because an unacceptable proportion of contaminants would be missed by limiting incubation to 7 days [60]. 

Assay Medium. Herrell el al. (16) recommend the use of fluid thioglycol-ate broth with the following composition yeast extract 5 g., Bacto-casitone 15 g., glucose 5 g., sodium chloride 2.5 g., Z-cystine 0.75 g., thioglycollic acid 0.3 ml., agar 0.75 g., resazurin (certified) 0.001 g., and distilled water 1 liter the final pH of this medium should be 7.1. 

---