Liofilchem Lysine Iron Agar

The Liofilchem™ Lysine Iron Agar (LIA) is a differential medium designed for the identification and differentiation of Enterobacteriaceae, particularly for detecting organisms capable of lysine decarboxylation and lysine deamination. This medium is commonly used in clinical, research, and food safety laboratories to isolate and differentiate Gram-negative bacteria based on their biochemical reactions.

Key Features

1. Biochemical Differentiation

• Allows the detection of lysine decarboxylase activity, lysine deamination, and hydrogen sulfide (H₂S) production.

2. Comprehensive Identification

• Differentiates Salmonella, Shigella, and other members of the Enterobacteriaceae family based on distinct biochemical characteristics.

3. pH-Dependent Color Changes

• Incorporates bromcresol purple, a pH indicator that facilitates easy interpretation of metabolic reactions:
  • Lysine decarboxylation: Alkaline reaction (purple slant and butt).
  • Lysine deamination: Reddish-brown slant.
  • H₂S production: Black precipitate in the medium.

4. Hydrogen Sulfide Detection

• Detects the production of H₂S by incorporating ferrous sulfate as an indicator.

5. Ready-to-Use

• Provided in an easy-to-prepare dehydrated format, simplifying laboratory workflows.

Applications

1. Clinical Diagnostics

• Differentiates Salmonella, Shigella, and other Enterobacteriaceae in stool, urine, and other clinical specimens.

2. Food and Water Testing

• Detects coliforms and other bacterial contaminants in food and water samples.

3. Research

• Supports studies on bacterial metabolism and identification of unknown Gram-negative isolates.

4. Veterinary Microbiology

• Used for testing Enterobacteriaceae in animal samples.

Storage and Handling

1. Storage Conditions:
   • Store dehydrated medium at 10–30°C in a tightly sealed container.
   • Prepared medium should be stored at 2–8°C and used within the specified shelf life.
2. Shelf Life:
   • Typically stable for 2 years under recommended conditions.
3. Preparation:
   • Dissolve the specified amount of dehydrated medium in distilled water.
   • Autoclave at 121°C for 15 minutes.
   • Cool to 50°C and pour into sterile test tubes or Petri dishes.

Typical Formula

Biochemical Reactions

1. Lysine Decarboxylation:
   • Results in an alkaline pH (purple slant and butt).
2. Lysine Deamination:
   • Produces a reddish-brown color on the slant.
3. Hydrogen Sulfide (H₂S) Production:
   • Black precipitate forms due to reaction with ferric ammonium citrate and sodium thiosulfate.
4. Glucose Fermentation:
   • Produces acid (yellow butt) in organisms unable to decarboxylate lysine.

Advantages

1. Comprehensive Differentiation:
   • Simultaneously evaluates lysine decarboxylation, deamination, and H₂S production.
2. Ease of Interpretation:
   • Distinct color changes for each reaction provide clear and reliable results.
3. Versatile Application:
   • Useful for both clinical and industrial microbiological testing.
4. High Sensitivity:
   • Reliable detection of biochemical activity in Enterobacteriaceae.

Why Choose Liofilchem™ Lysine Iron Agar?

The Liofilchem™ Lysine Iron Agar is an essential tool for laboratories needing reliable differentiation of Gram-negative bacteria. Its ability to detect multiple biochemical reactions in a single medium simplifies workflows and ensures accurate identification of clinically and industrially relevant organisms. The easy preparation and broad applicability make it a valuable addition to any microbiology laboratory.