Hemagglutination assay

Definition

A hemagglutination assay is a laboratory technique used to detect the presence of viruses or antibodies that cause red blood cells to agglutinate, or clump together. It is commonly used in virology for virus quantification and vaccine efficacy testing.

5 Must Know Facts For Your Next Test

1. Hemagglutination assays can be direct, detecting viral particles, or indirect, detecting antibodies against viruses.
2. The assay relies on the ability of certain viruses, such as influenza, to bind to sialic acid receptors on red blood cells.
3. A positive hemagglutination result indicates viral presence by showing visible clumping of red blood cells in the test sample.
4. Serial dilution of samples in a hemagglutination assay allows for quantifying the concentration of viral particles or antibodies.
5. Hemagglutination inhibition (HI) tests are a variation used specifically to measure the ability of antibodies to prevent virus-induced agglutination.

Review Questions

• What is the primary purpose of a hemagglutination assay?
• How does a positive result appear in a hemagglutination assay?
• What is the difference between direct and indirect hemagglutination assays?

Related terms

Plaque Assay: A method used to quantify virus particles based on their ability to form plaques on a cell monolayer.

ELISA (Enzyme-Linked Immunosorbent Assay): A plate-based assay technique designed for detecting and quantifying soluble substances such as peptides, proteins, antibodies, and hormones.

Hemadsorption: A phenomenon where certain viruses cause red blood cells to adhere to infected cell surfaces due to viral glycoproteins expressed on those surfaces.