Selenite Cystine Broth

Selenite cystine broth is a modification of selenite F broth and is for the selective enrichment of Salmonellae spp. from clinical, food and environmental specimens.
The peptone acts as a nitrogen, carbon and vitamin source. Lactose is a fermentable carbohydrate and sodium phosphate is a buffer. L-cystine is used to enhance the recovery of Salmonellae spp. in low numbers. 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.

Additional Information

Shelf Life (days)	1095 days
Storage Temp (°C)	10-30°C
Dehydrated Medium Appearance	Fine Powder
Prepared Medium Appearance	Liquid
Dehydrated Medium Colour	Beige
Prepared Medium Colour	Clear to Pale Orange
Dehydrated PH	7.1 ± 0.2
Prepared PH	7.1 ± 0.2
Recommended Incubation	Aerobically at 35-37°C for 18-24 hours

Product Description

Organisms	Ref. No	Result
Salmonella typhimurium	NCTC 12023	Growth
Escherichia coli	NCTC 12241	Inhibited

Formula*

	g/L
Peptone	5.0
Lactose	4.0
Sodium phosphate	10.0
L-Cystine	0.01
Total	19.0
*Adjusted/supplemented as required to meet performance requirements

Preparation

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.

Selenite Cystine Broth