Part of Thermo Fisher Scientific

Thermo Scentific
 
 
 

Dehydrated Culture Media

Sector: Clinical

THIOGLYCOLLATE MEDIUM USP

Code: CM0173

A medium for the cultivation of both aerobic and anaerobic organisms in the performance of sterility tests.

Formula

gm/litre

Yeast extract

5.0

Tryptone

15.0

Glucose

5.5

Sodium thioglycollate

0.5

Sodium chloride

2.5

L-cystine

0.5

Resazurin

0.001

Agar

0.75

pH 7.1 ± 0.2 @ 25°C

 


Directions
Suspend 29.75 g in 1 litre of distilled water. Bring to the boil to dissolve completely. Distribute into final containers, sterilise by autoclaving at 121°C for 15 minutes. Mix well and cool to room temperature.

Description
This medium is prepared according to the formula specified in the US Pharmacopoeia1 for the performance of sterility tests, and conforms to formulations detailed in the British, European and Japanese Pharmacopoeia2,3,4. It is suitable for the cultivation of both aerobic and anaerobic organisms. No paraffin or special seal is necessary, nor is an anaerobic jar required for the cultivation of anaerobes. It is well buffered so that acid or alkaline inocula produce negligible alteration in the reaction of the medium. The sodium thioglycollate content of the medium will neutralise the bacteriostatic effect of mercurial compounds used as preservatives in solutions for injection, etc. If the solution undergoing test contains a bacteriostatic substance it is necessary, in order to avoid a false negative result, to establish the bacteriostatic activity of the product by the method described in the US Pharmacopoeia1. Thioglycollate Medium USP is also recommended for the cultivation of Clostridium species. Sealey5 found that, of the media tested, Thioglycollate Medium USP gave the best results for the cultivation and maintenance of Desulfotomaculum nigrificans.

Microbiological quality control is carried out in accordance with the USP, BP, EP and ISO 11133:20146.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium away from light at room temperature.

Appearance
Dehydrated medium: Straw coloured, free-flowing powder.
Prepared medium: Straw-yellow coloured solution, with or without upper, red layer

Quality Control

Positive controls:

Expected results

Clostridium sporogenes ATCC®19404* Turbid growth and/or single colonies
Staphylococcus aureus ATCC® 6538 * Turbid growth and/or single colonies
Bacteroides vulgatus ATCC® 8482 * Turbid growth and/or single colonies
Candida albicans ATCC® 10231 * Turbid growth and/or single colonies
Bacillus subtilis ATCC® 6633 * Turbid growth and/or single colonies
Testing in accordance with ISO 11133:2014  
Clostridium perfringens ATCC® 13124
WDCM00007
Turbid growth and/or single colonies
Negative control:  
Uninoculated medium No change

* This organism is available as a Culti-Loop®

Precautions
If the upper portion of the medium is red because of oxidation, anaerobic conditions can be restored by reheating for 10 minutes in boiling water or steam. Do not reheat more than once.
Following reheating, if more than one-third of the medium is oxidised then it should be discarded.
Some glucose-fermenting organisms which are able to reduce the pH of the medium to a critical level may not survive in this medium. Early subculture is necessary to isolate these organisms.

References
1. US Pharmacopoeia.
2. British Pharmacopoeia
3. European Pharmacopoeia.
4. Japanese Pharmoacopoeia.
5. Sealey J. Q. (1951) Thesis of the University of Texas.
6. ISO 11133:2014 Microbiology of food, animal feed and water - Preparation, production, storage and performance testing of culture media

 
©2001 - 2020 Oxoid Limited, All rights reserved.
Copyright, Disclaimer and Privacy Policy | Conditions of Sale | About Us | Cookies
Thermo Fisher Scientific Inc.