Haemagglutination is a specific form of agglutination and is used when antibodies bind to red blood cells, which act as a particulate antigen. Red blood cells are particularly useful targets as they are readily available and agglutination is observable using the naked eye. This technique is commonly used to determine the titre of an antibody (Ab), for blood grouping and viral quantification. In...

A modification of the rubella haemagglutination inhibition (HAI) test in which both pretreatment and serum titration are carried out in wells of the same microtitre plate saves time, labour, and materials and gives results comparable to a conventional HAI procedure.

Newcastle disease virus (NDV) was isolated from a field outbreak in pigeons. The virus was characterized by haemagglutination test (HA) and confirmed by haemagglutination inhibition test (HAI). The pathotyping was done by mean death time (MDT), intracerebral pathogenicity index (ICPI) and intravenous pathogenicity index (IVPI). The ELD50 of the velogenic strain was 10/0.1 ml. Thirty-nine pigeon...

Investigations with antisera prepared in rabbits and sheep and active immunity experiments in mice showed that strains of Pasteurella multocida which, according to the haemagglutination test, are serologically related, do not necessarily give rise to cross immunity. Conversely, it was found that serologically unrelated strains may exhibit an appreciable degree of cross protection. The unreliabi...

Formaldehyde or gluteraldehyde cells treated with tannic acid were coated with plasminogen. These cells are agglutinated by plasminogen antiserum and this reaction can be quantitatively inhibited by purified plasminogen, plasma, and euglobulin. Correlation between this haemagglutination assay and a caseinolytic method is good. The sensitivity of the technique is high and compares favourably wit...

Several attempts have been made to use haemagglutination reactions for the diagnosis of syphilis between 1932 and 1958. The first reliable method was developed by Rathlev (1965). Further results of investigations with this method have been reported by authors from Japan and from the Venereal Disease Research Laboratory in Atlanta, U.S.A. Rathlev prepared the reagents for the test in the Statens...