Illustrative image only. Actual product may vary.MYP Agar Base
Also known as：MYP
For the isolation and enumeration of Bacillus cereus in food, following the addition of egg yolk emulsion and polymyxin B.
- Category
- Dehydrated Culture Media
- Dissolve per litre
- 46.03 g
- Pack sizes
- 500 g · 5 kg · 25 kg
Data updated：2026-11-06
Overview
MYP Agar Base (mannitol-egg yolk-polymyxin agar) is the standard count plate for Bacillus cereus: egg yolk emulsion and polymyxin B are added before use, polymyxin suppresses Gram-negative bacteria, B. cereus does not ferment mannitol and so keeps the pink of phenol red, and its lecithinase forms an opaque precipitation zone around the colony; the two features are read together. Specified by the Taiwan FDA B. cereus method, the FDA BAM and ISO 7932, it is a staple for testing cooked rice, boxed meals, dairy and infant foods. A base formulation; add egg yolk and polymyxin per the method.
Principle
MYP Agar was described by Mossel, Koopman and Jongerius for the enumeration of Bacillus cereus in foods.¹ Peptone and beef extract supply nitrogen, amino acids, vitamins, and growth factors, and sodium chloride maintains the osmotic equilibrium. Polymyxin B inhibits Gram-negative bacteria. Two reactions allow Bacillus cereus to be distinguished. It does not ferment mannitol, so its colonies remain pink to violet-red against a pink background, whereas mannitol-fermenting organisms produce acid that turns the phenol red indicator yellow. It also produces lecithinase, which hydrolyses the lecithin of egg yolk and forms a zone of white precipitate around the colonies. Typical colonies are large, rough, pink to violet-red, and surrounded by a precipitate zone.²
Directions
Suspend 46.025 g of powder in 900 mL of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and aseptically add 100 mL of 50% egg yolk emulsion and polymyxin B to give a final concentration of 100,000 IU/L. Mix well and pour into sterile Petri plates. Test the finished medium for performance using stable, standard control cultures.
Product highlights
- Manufactured to the standard formulation, 46.03 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
FDA BAM methods
This product corresponds to a medium used in the chapters of the US FDA Bacteriological Analytical Manual (BAM), the reference methods for FDA regulatory testing. Follow the current online edition of each chapter.
- FDA BAM Chapter 14: Bacillus cereusBAM Chapter 14Base mediumNamed in the method as：Mannitol-egg yolk-polymyxin (MYP) agar base
BAM specifies methods and media formulations; it does not certify brands. Add supplements as the chapter requires, and verify media against reference strains under your quality system.
Frequently asked questions
01Does this medium meet FDA BAM methods?
BAM specifies methods and formulations, not brands. This product corresponds to a medium used in: FDA BAM Chapter 14: Bacillus cereus（BAM Chapter 14）: Base medium. It is manufactured to the standard formulation and ships with a COA per batch; add supplements as the chapter requires and follow the current online edition.
02How much powder per litre?
Use 46.03 g per litre of deionised water; preparation and sterilisation conditions are given on the specification sheet.
03Which organisms is it suitable for?
Gram-positive, Pathogens, Aerobes, B. cereus. See the cultural response table and the specification sheet.
04How is this product prepared?
Suspend 46.025 g of powder in 900 mL of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 45-50°C and aseptically add 100 mL of 50% egg yolk emulsion and polymyxin B to give a final concentration of 100,000 IU/L. Mix well and pour into sterile Petri plates. 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.
Further reading
- FDA BAM Culture Media Cross-Reference: Which Media Each BAM Chapter Uses and the STBIO EquivalentAerobic plate count, coliforms and E. coli, Salmonella, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Vibrio, Clostridium perfringens, yeasts and moulds and Cronobacter: the media named in each FDA Bacteriological Analytical Manual chapter, matched to Taiwan-made dehydrated media for US laboratories qualifying a second source.
- Which Culture Media Do Taiwan FDA Food Microbiology Methods Specify? Cross-Reference for 21 Announced MethodsAerobic plate count, coliforms, E. coli, Enterobacteriaceae, Salmonella, Staphylococcus aureus, Listeria monocytogenes, lactic acid bacteria, yeasts and moulds, Bacillus cereus, Vibrio parahaemolyticus, Clostridium perfringens and Cronobacter: the media named in each Taiwan FDA (TFDA) announced method, matched to Taiwan-made products.
References
- 1. Mossel D. A. A., Koopman M. J. and Jongerius E., 1967. Enumeration of Bacillus cereus in foods. Appl. Microbiol., 15:650-653.
- 2. ISO 7932, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of presumptive Bacillus cereus — Colony-count technique at 30°C, International Organization for Standardization, Geneva.