title: Removal of HA1 subunit of HA monomer from influenza virions.
mesh_terms: D002499:Centrifugation, Density Gradient; D006389:Hemagglutinins, Viral / Q000032:analysis / Q000302:isolation & purification*; D009980:Influenza A virus / Q000276:immunology*; D008623:Mercaptoethanol; D014238:Trichloroacetic Acid; D014771:Virion / Q000276:immunology
chemical_list: D006389:Hemagglutinins, Viral; D014238:Trichloroacetic Acid; D008623:Mercaptoethanol