MacConkey Broth
Also known as：MacConkey Broth Purple · MacConkey Purple Broth · MacConkey Broth with Bromocresol Purple · MCB
For the presumptive detection of coliform organisms in water, milk, and other materials by the multiple-tube fermentation technique.
- Category
- Dehydrated Culture Media
- Dissolve per litre
- 35.01 g
- Pack sizes
- 500 g · 5 kg · 25 kg
- Certifications
- Halal
Data updated：2026-11-06
Overview
MacConkey Broth is a broth (liquid) medium, a selective medium for food and clinical testing that suppresses competing flora and makes target colonies recognisable. Bile salts and crystal violet suppress Gram-positives; lactose fermentation distinguishes coliforms from other enteric bacilli. STBIO manufactures it from food-grade raw materials in an ISO 22000 certified facility, with a COA for every batch. This is the Halal-certified version.
Principle
MacConkey Broth derives from the bile salt lactose medium described by MacConkey for the detection of lactose-fermenting enteric bacteria.¹ Pancreatic digest of gelatin supplies nitrogen, amino acids, and peptides, and lactose serves as the fermentable carbohydrate. Oxgall inhibits Gram-positive and non-enteric organisms while permitting the growth of coliforms. Coliforms ferment lactose with the production of acid and gas. The acid changes the bromocresol purple indicator from purple to yellow, and gas collects in the Durham tube. Tubes showing both acid and gas are regarded as presumptive positive and require confirmation on a selective confirmatory medium.²
How selective media fit into the testing workflow
Pathogen testing normally runs in three stages: a pre-enrichment medium such as Buffered Peptone Water repairs injured cells and raises numbers, a selective enrichment then suppresses competing flora, and finally a selective differential agar isolates the target colonies. Selective agents are typically bile salts, dyes, or antibiotics; differential agents make target colonies develop a characteristic colour or morphology. Choose the combination specified by the method you follow.
Directions
Suspend 35.01 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Dispense into tubes containing inverted Durham tubes. Sterilize by autoclaving at 121°C for 15 minutes. Test the finished medium for performance using stable, standard control cultures.
Cultural response
| Test organism | ATCC | Growth |
|---|---|---|
| Escherichia coli | 25922 | good-luxuriant |
| Klebsiella aerogenes | 13048 | good-luxuriant |
| Salmonella enterica ser. Typhimurium | 14028 | good-luxuriant |
| Staphylococcus aureus | 25923 | inhibited |
Product highlights
- Halal certified, suitable for the Malaysian, Indonesian, and Middle Eastern markets
- Manufactured to the standard formulation, 35.01 g per litre
- Performance verified against standard control strains before release (Escherichia coli, Klebsiella aerogenes, Salmonella enterica ser. Typhimurium, Staphylococcus aureus)
- 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
01Can selective media be autoclaved?
Not always. Some media containing dyes or selective inhibitors lose their selectivity if overheated and should only be heated until fully dissolved, without autoclaving. Follow the preparation instructions for this product, and contact us if you are unsure.
02How much powder per litre?
Use 35.01 g per litre of deionised water; preparation and sterilisation conditions are given on the specification sheet.
03Which organisms is it suitable for?
Coliforms, Enterobacteriaceae, Gram-negative, E. coli, Escherichia coli, Klebsiella aerogenes, Salmonella enterica ser. Typhimurium, Staphylococcus aureus. See the cultural response table and the specification sheet.
04How is this product prepared?
Suspend 35.01 g of powder in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Dispense into tubes containing inverted Durham tubes. Sterilize by autoclaving at 121°C for 15 minutes. Test the finished medium for performance using stable, standard control cultures.
05How 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.
Used in these applications
References
- 1. MacConkey A. T., 1905. Lactose-fermenting bacteria in faeces. J. Hyg., 5:333-379.
- 2. MacFaddin J. F., 1985. Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria, Williams & Wilkins, Baltimore.