Ferric Ammonium Citrate (FAC) Supplement
E&O Laboratories Ltd Ferric Ammonium Citrate (LS5004) is a
supplement used in the isolation of Listeria spp. with Fraser Broth. Fraser Broth is a modification of the USDA-FSIS (United States Department of Agriculture-Food Safety Inspection Service) UVM secondary enrichment broth and is based on the formula described by Fraser and Sperber. Blackening of the medium is presumptive evidence of the presence of Listeria. Contrary to early indications, cultures which do not blacken cannot be assumed to be Listeria-free. All Fraser Broth enrichment cultures should be subcultured to plating medium.
The medium is intended for the isolation of Listeria spp. from food and environmental samples when used as the secondary enrichment medium in the USDA-FSIS methodology for Listeria isolation. It is generally accepted that the USDA-FSIS two stage enrichment
method employing UVM primary and secondary enrichment broths is the most suitable for the examination of meat products.
Ferric Ammonium Citrate
Additional Information
| Shelf Life (days) | |
|---|---|
| Storage Temp (°C) | |
| Dehydrated Medium Appearance | |
| Dehydrated Medium Colour | |
| pH | |
| Solubility Description | |
| Recommended Incubation |
Product Description
| Organisms | Ref. No | Result |
| Listeria monocytogenes | NCTC 11994 | Growth & Black colonies |
Formula
| Vial Contents | per Vial | per Litre |
| Ferric ammonium citrate | 0.25g | 0.5g |
Procedure
Suspend the recommended manufacturer’s amount of dehydrated media in 500ml of distilled water and mix well to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 45-50°C, and aseptically add the contents of one vial of Ferric Ammonium Citrate (LS5004).To reconstitute vial add 2 mls of distilled water and mix before addition to the supplemented
dehydrated media.