Liofilchem™ Lysine decarboxylase Test, 30 Tests

Rapid Biochemical Assay for Differentiation of Enterobacteriaceae and Gram-Negative Bacteria

The Liofilchem® Lysine Decarboxylase Test is a rapid, qualitative biochemical assay designed to identify and differentiate Enterobacteriaceae and other gram-negative bacteria based on lysine decarboxylase activity. It serves as an aid in microbial diagnosis and is intended for professional use in clinical microbiology, food testing, pharmaceutical, and environmental laboratories.

Test Principle

The test detects the enzymatic activity of lysine decarboxylase, which catalyzes the decarboxylation of lysine to cadaverine. This activity results in a measurable pH change:

• Initial acidification of the medium (yellow color) occurs due to glucose fermentation.
• If lysine decarboxylase is present, cadaverine is produced, alkalizing the medium and restoring the color to purple.
• A positive result is indicated by a purple color; a negative result remains yellow.

Kit Components

• 30 test tubes containing dehydrated biochemical substrates including lysine, glucose, bromocresol purple (indicator), and pyridoxal.
• Color-coded indicator system
• Designed for use with pure cultures

Test Procedure

1. Bring tubes to room temperature.
2. Add 0.3 mL of physiological saline to each tube.
3. Inoculate with the test organism.
4. Overlay with 2–3 drops of sterile mineral oil.
5. Incubate at 35 ± 2°C for up to 96 hours.
6. Observe for color change starting at 4 hours, then daily.

Interpretation of Results

Performance & Quality Control

• Klebsiella pneumoniae ATCC® 13383: Positive (purple)
• Escherichia coli ATCC® 25922: Positive (purple)
• Proteus mirabilis ATCC® 25923: Negative (yellow)

Specifications

• Product Code: 88014
• Shelf Life: 1 year
• Storage: 2–8°C
• Appearance: Violet powder; yellow-red solution after reconstitution
• Intended Use: In vitro diagnostics (IVD)

Applications

• Clinical identification of Salmonella, Shigella, Escherichia, Klebsiella, and Proteus spp.
• Microbial differentiation in pharmaceutical and food safety testing
• Educational use in teaching labs for biochemical identification procedures

Safety and Handling

• For IVD use only.
• Use appropriate personal protective equipment.
• Dispose of all materials in compliance with local biosafety regulations.

The Liofilchem® Lysine Decarboxylase Test is a robust, rapid tool for screening bacterial isolates for lysine decarboxylase activity. Its ready-to-use format, clear interpretive results, and reliability make it an essential component of modern microbial diagnostic workflows, particularly in differentiating members of the Enterobacteriaceae family and other glucose-fermenting gram-negative bacteria.