Developed by Leifson, selenite F broth is a medium for the selective enrichment of Salmonella spp. from both clinical and food samples.
The peptone acts as a nitrogen, carbon and vitamin source. Lactose is a fermentable carbohydrate and sodium phosphate is a buffer. The medium is made selective by the addition of sodium biselenite (KM8021).
Following overnight incubation subculture(s) are usually made on to one or more of the many selective enteric solid media.
| Shelf Life (days) | |
|---|---|
| Storage Temp (°C) | |
| Dehydrated Medium Appearance | |
| Prepared Medium Appearance | |
| Dehydrated Medium Colour | |
| Prepared Medium Colour | |
| Dehydrated PH | |
| Prepared PH | |
| Recommended Incubation |
| Organisms | Ref. No | Result |
| Salmonella typhimurium | NCTC 12023 | Growth |
| Escherichia coli | NCTC 12241 | Inhibited |
| g/L | |
| Peptone | 5.0 |
| Lactose | 4.0 |
| Sodium phosphate | 10.0 |
| Total | 19.0 |
| *Adjusted/supplemented as required to meet performance requirements | |
Suspend 19 g of the medium in one litre of deionised / purified water. Add 4 g of sodium bi-selenite (KM8021). Allow the medium to soak whilst mixing for 10 minutes. Heat with frequent agitation until boiling. Cool to 45-50°C, mix well and aseptically dispense into appropriate sterile containers.
To minimise any possible risk of teratogenicity to laboratory workers, the sodium biselenite must be added to this medium separately.