A sensitive, single-radial diffusion autoradiographic zone size enhancement technique for the assay of influenza haemagglutinin.
A novel radial-diffusion technique in agarose gels is described which is applicable to the assay of small concentrations of influenza haemagglutinin (HA) antigen. The method is based on single-radial diffusion zone size enhancement (ZE) using autoradiography to demonstrate antigen--antibody reactions. The ZE technique is capable of reliably assaying concentrations of haemagglutinin as low as 0.1 microgram/ml, which represents a 20- to 40-fold increase in sensitivity over conventional single-radial-diffusion techniques. The ZE response is dependent upon the antigenic identity of the 125I-labelled 'marker' HA and the HA antigen being assayed. Haemagglutinins showing variation within a subtype (e.g. H3) show reduced ZE responses and thus the method has potential value for distinguishing between closely related HA antigens.
D001345:Autoradiography; D006389:Hemagglutinins, Viral / Q000032:analysis* / Q000145:classification; D005779:Immunodiffusion / Q000379:methods*; D009980:Influenza A virus / Q000276:immunology*; D009975:Orthomyxoviridae / Q000276:immunology
D006389:Hemagglutinins, Viral