Limulus amebocyte lysate (LAL) test

Definition

The Limulus amebocyte lysate (LAL) test is a biochemical assay used to detect bacterial endotoxins. It utilizes the blood of horseshoe crabs, which coagulates in the presence of endotoxins.

5 Must Know Facts For Your Next Test

1. The LAL test is crucial for ensuring the sterility of medical devices and pharmaceuticals.
2. Endotoxins are components of the outer membrane of Gram-negative bacteria that can cause severe immune responses in humans.
3. Horseshoe crab blood contains amebocytes, which react with bacterial endotoxins by forming a gel clot.
4. The LAL test can be performed using various methods including gel-clot, turbidimetric, and chromogenic assays.
5. Regulatory agencies like the FDA require LAL testing for certain medical products to ensure safety.

Review Questions

• What type of bacterial component does the LAL test detect?
• Why is horseshoe crab blood used in the LAL test?
• Name two methods other than gel-clot that are used in performing the LAL test.

Related terms

Endotoxin: Toxic components found in the outer membrane of Gram-negative bacteria.

Amebocytes: Cells found in horseshoe crab blood that play a role in coagulation when exposed to endotoxins.

Chromogenic Assay: A method involving color change to measure the presence and concentration of substances, such as endotoxins.