Haemagglutination inhibition tests are easy to perform and easy to read. The results are reproducible and are not subject to the vagaries of supply and temperament inherent in tests using living creatures. In a series of tests with Prepuerin done in parallel with the Hogben test the former has shown a higher sensitivity. There have been three false positive results with Prepuerin tests in the s...

Let S be an abelian semigroup, written additively, that contains the identity element 0. Let A be a nonempty subset of S. The cardinality of A is denoted |A|. For any positive integer h, the sumset hA is the set of all sums of h not necessarily distinct elements of A. We define hA = {0} if h = 0. Let A1, . . . , Ar, and B be nonempty subsets of S, and let h1, . . . , hr be nonnegative integers....

Sheep erythrocytes were treated with glutaraldehyde before sensitization for the indirect hemagglutination test to assay chlamydial antibodies. This treatment markedly increased stability during storage.

Nontreponemal antibody tests such as the Venereal Disease Research Laboratory (VDRL) test are carried out on serum and widely used as screening tests for syphilis. The aim of the present study was to develop a screening test for syphilis making use of whole blood and VDRL liposomes. Antibody to human red blood cells was conjugated to VDRL liposomes and reacted with a diluted sample of patient w...

Nonspecific reactions by the passive hemagglutination test for rubella viral antibody occurred with 1.5% of sera tested. Rises in passive hemagglutination titers (greater than or equal to 4X) occurred with some serum samples taken 14 days after vaccination.

to detect the presence of infectious bronchitis virus (ibv) in infected allantoic fluid (af) of spf embryonated eggs rapid hemagglutination (ha) activity after treatment with neuraminidase enzyme was used. twenty ibv suspected materials were inoculated in spf embryonated eggs via chorioallantoic cavity. harvested afs were treated with neuraminidase enzyme and the presence of ibv was detected by...

Nonspecific inhibitors of rubella hemagglutination can be removed by treatment of sera with heparin-manganous chloride for use in the hemagglutination-inhibition test. After removal of nonspecific inhibitors by this procedure, an excess of manganous chloride may remain. This may cause the cells to agglutinate, thus obscuring the reading at low serum dilutions. This disadvantage can be overcome ...