Laboratory Nopha
ChemMallEndotoxin & Microbe Controlled
Principles and Common Interference Factors of LAL Assay for Endotoxin Testing

Principles and Common Interference Factors of LAL Assay for Endotoxin Testing

5/10/2026140 views

Principles and Common Interference Factors of LAL Assay for Endotoxin Testing

In the biopharmaceutical industry, the most classic and authoritative method for detecting bacterial endotoxins is the Limulus Amebocyte Lysate (LAL) assay.

Basic Principles of LAL

LAL is an extract of blood cells from the horseshoe crab. When encountering endotoxins, it activates a series of enzymatic reactions, forming a gel or causing turbidity/color changes.

Common Interference Factors

  1. pH Deviation: Optimal pH range is 6.0 - 8.0.
  2. Heavy Metal Ions: Can inhibit enzyme reactions.
  3. Chelating Agents (e.g., EDTA): Take away calcium ions necessary for enzyme reactions.