Liofilchem® Yeast Glucose Chloramphenicol Agar (YGC Agar)

Liofilchem® Yeast Glucose Chloramphenicol Agar (YGC Agar) is a selective culture medium specifically formulated for the isolation and enumeration of yeasts and moulds in foodstuffs, beverages, milk, and dairy products.

The medium is widely used in food microbiology quality control laboratories, as it complies with the International Dairy Federation (FIL-IDF / ISO 6611 / IDF 94) recommendations for the examination of milk and milk products. The inclusion of chloramphenicol effectively suppresses bacterial growth, allowing optimal recovery of fungal organisms, including stressed or injured cells.

Intended Use

YGC Agar is intended for:

• Selective isolation of yeasts and moulds
• Quantitative enumeration of fungi in food and beverages
• Routine quality control testing
• Regulatory and standard-compliance microbiology testing

Principle of the Medium

• Yeast extract supplies essential nutrients and B-group vitamins
• Glucose serves as a fermentable carbohydrate, promoting fungal growth
• Chloramphenicol inhibits accompanying bacterial flora, improving selectivity
• Agar acts as the solidifying agent

This formulation ensures excellent recovery of yeasts and moulds, even when bacterial contamination is present.

Typical Formula (g/L)

Preparation Instructions

Dehydrated Medium

1. Suspend 43.1 g of powder in 1 L of distilled or deionized water
2. Mix thoroughly
3. Heat to boiling with frequent agitation until completely dissolved
4. Sterilize by autoclaving at 121 °C for 15 minutes

Medium in Bottles

1. Melt the medium in a 100 °C water bath (cap loosened)
2. Tighten cap and mix to ensure homogeneity
3. Cool to 45–50 °C
4. Aseptically dispense into Petri dishes

Test Procedure

1. Prepare sample dilutions using ¼-strength Ringer’s Solution or equivalent diluent
2. Inoculate using:
   • Pour plating
   • Spread plating
   • Membrane filtration (filters placed on 60 mm YGC plates)
3. Incubate aerobically at 25 ± 2 °C
4. Incubation time: up to 5 days

Interpretation of Results

• Count plates with 15–300 colonies
• Distinguish yeasts from moulds based on colony morphology
• Report results as:
  • CFU/g (solid samples)
  • CFU/mL (liquid samples)

Appearance

• Dehydrated medium: Free-flowing, homogeneous, beige
• Prepared medium: Slightly opalescent, light amber

Quality Control

The medium is quality-controlled using the following reference strains:

Storage & Shelf Life

Do not use beyond expiry date or if contamination/deterioration is observed.

Applications

• Food microbiology laboratories
• Dairy and beverage quality control
• Environmental and industrial hygiene testing
• Regulatory compliance testing
• Research and teaching laboratories

Safety & Disposal

• Not classified as hazardous under current legislation
• Professional laboratory use only
• Consult the Safety Data Sheet (SDS)
• Dispose of waste according to national and local regulations

Available Formats & Ordering Information

Liofilchem® Yeast Glucose Chloramphenicol Agar is a high-performance, selective medium for the reliable detection and enumeration of yeasts and moulds in food and beverage testing. Its validated selectivity, regulatory compliance, and availability in multiple formats make it a trusted choice for routine quality control and standard-based microbiological analysis.