The diagnostic value of the hemagglutination inhibition test for Newcastle disease has been established for some years (Brandly et al., 1946). The question of the relationship of the hemagglutination inhibition activity (HI) of immune sera to virus-neutralizing activity (SN) or to the refractivity of the host to challenge infection is still one of both fundamental and practical importance. Data...

The hemagglutination-inhibition (HI) test for antirhinovirus antibody was carried out on paired sera from volunteers inoculated with rhinovirus type 3 or type 4 (RV4). The HI test gave results which paralleled the neutralization test and was at least as sensitive as a microneutralization method for detection of serotype-specific antibody. Although high levels of HI antibody in the serum were as...

A hemagglutination inhibition (HI) test has been studied as an alternative to bacterial agglutination (BA) for serogrouping strains of Neisseria meningitidis isolated from clinical specimens. The HI test consists of polysaccharide antigens adsorbed to sheep red blood cells which were then agglutinated by group-specific antisera. Supernatant fluids from suspensions of meningococci were used to i...

The virus neutralization (VN) test was used to determine potency of the infectious bronchitis (IB) vaccine. The results of VN, hemagglutination inhibition (HI), and enzyme-linked immunosorbent assay (ELISA) were compared with those of the IBV M41. The r values between VN and HI titers and the ELISA antibody titer were 0.8782 and 0.0336, respectively, indicating a high correlation between VN and...

A dot immunobinding assay ( DIA) was used for a quantitative and qualitative assay of rubella antibody. Purified antigen and conjugated anti-human immunoglobulin (RAHlg) were prepared. Nitrocellulose paper dotted with the antigen was added to serially diluted sera or blood samples. The reacting antibodies were visualized by a peroxidase system. Development of a colored insoluble substrate ...

Acute and convalescent plasma samples were obtained from 101 confirmed primary dengue cases: 48 cases infected with dengue virus type 1, 10 cases with type 2, 42 cases with type 3 and one case with type 4. The hemagglutination inhibition (HI) titers of individual samples were at levels similar to each of the 4 dengue viruses at both the acute and convalescent stages, irrespective of the dengue ...

Single radial hemolysis (SRH), neutralization (NT), and hemagglutination inhibition (HI) tests were carried out on sera from horses immunized against the Prague and Miami strains of equine influenza virus. The HI and NT tests demonstrated good sensitivity; the sensitivity of the SRH test was somewhat lower. The NT titers of individual sera were correlated very closely with the HI titers, althou...

An enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies against the pandemic H1N1 2009 influenza A virus, employing a recombinant hemagglutinin protein of the virus, was compared to the hemagglutination inhibition (HI) test using 783 serum samples. The results showed a concordance of 98.4%, suggesting the utility of the ELISA in serosurveillance. Two hundred sixty-nine ...

An enzyme-linked immunosorbent assay (ELISA) and the hemagglutination inhibition (HI) test were used to evaluate the response of laboratory rats to experimental infection with pneumonia virus of mice. The ELISA procedure was more sensitive than the HI test and detected very low levels of antibodies early in the course of infection. At 5 days postinfection, ELISA detected antibody increases in f...

A hemagglutination-inhibition (HI) test for rubella is described which utilizes human group O, rather than 1-day-old chick, erythrocytes. The test was found to be as sensitive and reproducible for detection of rubella antibody as HI tests employing chick erythrocytes. Advantages to the use of human erythrocytes are (i) they are more available, (ii) it is unnecessary to absorb natural agglutinin...