Illustrative image only. Actual product may vary.Giolitti-Cantoni Broth Base
Also known as：GC Broth · Giolitti-Cantoni Broth · Giolitti and Cantoni Broth · Giolitti-Cantoni Staphylococcus Enrichment Broth
For the selective enrichment of Staphylococcus aureus from food, following the addition of potassium tellurite.
- Category
- Dehydrated Culture Media
- Dissolve per litre
- 54.2 g
- Pack sizes
- 500 g · 5 kg · 25 kg
Data updated：2026-11-06
Overview
Giolitti-Cantoni Broth Base (GC enrichment broth) is the selective enrichment broth for the Staphylococcus aureus MPN method and low-count samples: lithium chloride and the potassium tellurite added before use suppress competing flora, while mannitol and sodium pyruvate help injured staphylococci recover; blackening or a black precipitate after incubation is a presumptive positive, confirmed by streaking on Baird-Parker plates. Specified by ISO 6888-3 and suited to milk powder, infant foods and processed samples with low counts. A base formulation; add potassium tellurite per the method.
Principle
Giolitti-Cantoni Broth was described by Giolitti and Cantoni for the enrichment of staphylococci from foods.¹ Tryptone, meat extract, and yeast extract supply nitrogen, amino acids, vitamins, and growth factors. Mannitol, glycine, and sodium pyruvate stimulate the growth of Staphylococcus aureus; sodium pyruvate also degrades hydrogen peroxide and assists the recovery of sub-lethally injured cells. Lithium chloride and potassium tellurite inhibit Gram-negative bacteria and most Gram-positive organisms other than Staphylococcus aureus. Sealing the tubes with paraffin creates anaerobic conditions that suppress micrococci, while the facultatively anaerobic Staphylococcus aureus continues to grow. Staphylococcus aureus reduces tellurite to metallic tellurium, producing blackening of the medium, which is taken as a presumptive positive result. Blackened tubes are subcultured onto Baird-Parker Agar for confirmation.²
Directions
Suspend 54.2 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Dispense into tubes. Sterilize by autoclaving at 121°C for 15 minutes. Cool and aseptically add sterile potassium tellurite solution to the concentration specified in the applicable method. After inoculation, seal each tube with a layer of sterile molten paraffin or agar. Test the finished medium for performance using stable, standard control cultures.
Product highlights
- Manufactured to the standard formulation, 54.2 g per litre
- 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 54.2 g per litre of deionised water; preparation and sterilisation conditions are given on the specification sheet.
02Which organisms is it suitable for?
Pathogens, Gram-positive, S. aureus. See the cultural response table and the specification sheet.
03How is this product prepared?
Suspend 54.2 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Dispense into tubes. Sterilize by autoclaving at 121°C for 15 minutes. Cool and aseptically add sterile potassium tellurite solution to the concentration specified in the applicable method. After inoculation, seal each tube with a layer of sterile molten paraffin or agar. 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.
References
- 1. Giolitti G. and Cantoni C., 1966. A medium for the isolation of staphylococci from foodstuffs. J. Appl. Bacteriol., 29:395-398.
- 2. ISO 6888-3, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of coagulase-positive staphylococci — Part 3: Detection and MPN technique for low numbers, International Organization for Standardization, Geneva.