Illustrative image only. Actual product may vary.Selenite Cystine Broth Base
Also known as：SC · Selenite Cystine Broth Base w/o Biselenite
For the selective enrichment of Salmonella species from food, water, and other materials, following the addition of sodium hydrogen selenite.
- Category
- Dehydrated Culture Media
- Dissolve per litre
- 19.01 g
- Pack sizes
- 500 g · 5 kg · 25 kg
Data updated：2026-11-06
Overview
Selenite Cystine Broth Base (SC) is a selective enrichment broth for Salmonella: sodium selenite suppresses coliforms, enterococci and other competing flora, cystine improves recovery of Salmonella and phosphate holds the pH. The Taiwan FDA Salmonella method and the FDA BAM transfer the pre-enrichment culture into SC and tetrathionate broth in parallel before streaking the isolation plates. Selenite is heat-labile, so the broth is heated to dissolve, not autoclaved, and used the same day. A base formulation to be adjusted per the method.
Principle
Selenite enrichment broth was introduced by Leifson for the isolation of Salmonella, and the addition of L-cystine by North and Bartram improved its recovery.¹ʼ² Tryptone supplies nitrogen, amino acids, and peptides. Sodium hydrogen selenite is the selective agent: it inhibits Gram-positive bacteria and many Gram-negative organisms, including coliforms and enterococci, during the first 6 to 12 hours of incubation, while Salmonella is relatively tolerant. Lactose is fermented by the competing flora, and the resulting acid, together with the phosphate buffer, holds the pH in the range in which selenite remains effective; a rise in pH would reduce its toxicity to competing organisms. L-Cystine acts as a reducing agent and enhances the recovery of Salmonella. Growth is indicated by turbidity, often with a red precipitate of reduced selenium, and enrichment cultures are subcultured onto selective plating media.³
Media for anaerobes and fastidious organisms
Anaerobes and fastidious organisms require media containing reducing agents, blood, or infusion components, together with an anaerobic incubation environment. Some formulations need heat-labile supplements such as blood, serum, or antibiotics added after sterilisation; follow the preparation instructions for the timing and method.
Directions
Suspend 19.01 g of powder in 1 L of purified water containing 4 g of sodium hydrogen selenite. Heat with continuous stirring and bring to the boil for 1 minute. DO NOT AUTOCLAVE. Dispense into sterile tubes and use on the day of preparation. Test the finished medium for performance using stable, standard control cultures.
Cultural response
| Test organism | ATCC | Growth |
|---|---|---|
| Salmonella enterica ser. Typhimurium | 14028 | good-luxuriant |
| Salmonella enterica ser. Enteritidis | 13076 | good-luxuriant |
| Escherichia coli | 25922 | inhibited-partial |
| Enterococcus faecalis | 29212 | inhibited |
Product highlights
- Manufactured to the standard formulation, 19.01 g per litre
- Performance verified against standard control strains before release (Salmonella enterica ser. Typhimurium, Salmonella enterica ser. Enteritidis, Escherichia coli, Enterococcus faecalis)
- Available in 500 g / 5 kg / 25 kg, from laboratory to industrial scale
- COA, specification sheet, and technical data sheet available; samples on request
- Manufactured in Taiwan with reliable supply
Frequently asked questions
01How much powder per litre?
Use 19.01 g per litre of deionised water; preparation and sterilisation conditions are given on the specification sheet.
02Which organisms is it suitable for?
Enterobacteriaceae, Gram-negative, Pathogens, Salmonella, Salmonella enterica ser. Typhimurium, Salmonella enterica ser. Enteritidis, Escherichia coli, Enterococcus faecalis. See the cultural response table and the specification sheet.
03How is this product prepared?
Suspend 19.01 g of powder in 1 L of purified water containing 4 g of sodium hydrogen selenite. Heat with continuous stirring and bring to the boil for 1 minute. DO NOT AUTOCLAVE. Dispense into sterile tubes and use on the day of preparation. Test the finished medium for performance using stable, standard control cultures.
04How do I request a bulk quotation, and can you provide a COA?
Yes. This product is available in 500 g, 5 kg, 25 kg. Tell us your application and volume when requesting a quotation; we reply within one working day and can supply the COA, specification sheet, and technical data sheet.
Further reading
References
- 1. Leifson E., 1936. New selenite enrichment media for the isolation of typhoid and paratyphoid (Salmonella) bacilli. Am. J. Hyg., 24:423-432.
- 2. North W. R. and Bartram M. T., 1953. The efficiency of selenite broth of different compositions in the isolation of Salmonella. Appl. Microbiol., 1:130-134.
- 3. U.S. Food and Drug Administration, Bacteriological Analytical Manual, Chapter 5, Salmonella.