C24H39NaO5 (NaC); C24H39NaO4 (NaD)
Sodium cholate and sodium deoxycholate are the sodium salts of cholic and deoxycholic acid, offered as single products.
Bile Salts 3 is a mixture of the two salts, sodium cholate and sodium deoxycholate, which was developed specifically for microbiological applications.
NZP Special Bile is a refined bile product containing the natural conjugated bile acids and is used as a selective inhibitory agent in microbiological media. It differs from Ox Bile Extract in several ways, thus is preferred for media such as MacConkey broth and agar, Brilliant Green Bile Broth and EE Broth.
Special Bile contains a mixture of conjugated bile salts, predominantly sodium glycocholate and sodium taurocholate along with a small amount of free bile acids (cholic acid). The refining process has been designed to remove lipids and reduce the pigments in the bile, thus making it a useful component of selective broths.
Features of Special Bile:
- The Bile used for Special Bile is carefully selected to contain very low levels (<0.5% w/w) of free Deoxycholic Acid. Bile powders with high levels of Deoxycholic Acid demonstrate a toxicity that may be unacceptable for eg. MacConkey media and EE Broth.
- The colour of Special Bile is carefully controlled in order to provide media suppliers with a consistent product for MacConkey and Brilliant Green Bile Broths, by being light enough in colour for effective and consistent dye coloration.
- Unlike crude Bile Powders, the product will not form a surface scum or a deposit in culture media.
Bacteriological performance of Special Bile.
MacConkey Broth and Agar made with Special Bile at the Minimum Effective Concentration supports satisfactory growth of bile tolerant organisms, including pathogenic staphylococci. Gas production by clostridia is inhibited in broths containing higher concentrations of Special Bile (eg. Brilliant Green Bile Broth), therefore eliminating false positives for E.coli.
These are just a couple of examples of the advantages seen by culture media manufacturers for the use of Special Bile in their selective media.
Use of Chemical
All of the above bile salts are used in microbiological culture media. A major use is in clinical microbiology to selectively grow faecal staphylococci and streptococci (MacConkey Agar CM7/7b).
- CAS Number: 361-09-1 (NaC); 302-95-4 (NaD)
- Molecular Weight: 430.6 (NaC); 414.6 (NaD)
- Solubility: Water soluble
- Packaging: All bile salt products are sealed in a polyethylene liner and packaged in 20 kg fibre drums. Customer specific packaging can be provided.