Hemagglutination Assay for the Avian Influenza Virus

  • Mary Lea Killian
Part of the Methods in Molecular Biology™ book series (MIMB, volume 436)


The hemagglutination (HA) assay is a tool used to screen cell culture or amnioallantoic fluid harvested from embryonating chicken eggs for hemagglutinating agents, such as type A influenza. The HA assay is not an identification assay, as other agents also have hemagglutinating properties. Live and inactivated viruses are detected by the HA test. Amplification by virus isolation in embryonating chicken eggs or cell culture is typically required before HA activity can be detected from a clinical sample. The test is, to some extent, quantitative [1 hemagglutinating unit (HAU) is equal to approximately 5–6 logs of virus]. It is inexpensive and relatively simple to conduct. Several factors (quality of chicken erythrocytes, laboratory temperature, laboratory equipment, technical expertise of the user) may contribute to slight differences in the interpretation of the test each time it is run. This chapter will describe the methods validated and used by the National Veterinary Services Laboratories (NVSL) for screening and identification of hemagglutinating viruses.


hemagglutination amnioallantoic fluid erythrocyte 


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Copyright information

© Humana Press, a part of Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Mary Lea Killian
    • 1
  1. 1.Avian Viruses Section, Diagnostic Virology Laboratory, National Veterinary Services LaboratoriesUS Department of AgricultureAmesIA

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