Hemagglutination Assay (HA)

Overview
A classical assay for detecting and quantifying viruses (e.g., influenza) that agglutinate red blood cells.

Principle

• Serial dilutions of virus are incubated with RBCs.

• Agglutination is visually assessed.

• The highest dilution causing complete agglutination is recorded as the HA titer.

Applications

• Virus quantification for influenza and other HA viruses

• Standardization of input material for HAI assays

• Rapid viral load estimation

Deliverables from MIV
✔️ HA titers reported in HA units
✔️ Well plate images for documentation
✔️ Technical interpretation for assay planning