A simple and rapid immunoassay of morphine based on latex agglutination inhibition reaction has been developed. Morphine-6-succinate is a morphine derivative, and its bovine serum albumin (BSA) conjugates were synthesized and characterized. The hapten density in the conjugate was determined spectroscopically to be 8.2 mol per mol of BSA. It was found that morphine-6-succinyl-BSA (M-6-S-BSA) exh...

A sialoglycoprotein from horse erythrocytes was isolated in essentially homogeneous form and found to contain the neuraminidase-sensitive determinant of the horse erythrocyte for Paul-Bunnell heterophile antibodies of infectious mononucleosis. This reactivity was retained after covalent coupling of the antigen to latex particles. The latex reagent has greater stability (greater than 3 years) th...

A new non isotopic immunoassay based on latex particle agglutination has been developed for the determination of albumin in urine. The assay consists in incubating the urine sample for 30 min at 37 degrees C with latex particles coated with a specific antibody, followed by quantification of the resulting agglutination by particle counting or turbidimetry. The stability of antibody-coated partic...

The ability of 135 Staphylococcus strains isolated from Spanish dry-cured hams to produce enterotoxins in culture was investigated by the reversed passive latex agglutination method. A high percentage of enterotoxigenic Staphylococcus aureus strains (85.9%) was recorded, and 54.3% of these produced enterotoxin A. One of the two Staphylococcus epidermidis strains produced enterotoxin C. The reve...

Latex agglutination was compared with fluorescent-antibody staining with group A conjugate and Lancefield precipitation for grouping of beta-hemolytic streptococci. Latex agglutination correctly grouped 98.8% of 82 group A streptococci and more than 95% of 187 group B, C, or G streptococci. Occasional cross-reactions occurred between groups A and C and groups B and G.

A sensitive latex immunoassay for human serum lipoprotein Lp(a+) is based on direct agglutination by Lp(a+) of latex particles coated with specific antibody. The agglutination is quantified by turbidimetry using a photometer at 360 nm. The stabilization of antibody-coated latex particles by bovine serum albumin occurs under well-defined conditions (pH, concentration of bovine serum albumin, and...

A stool sample from a child with haemorrhagic colitis and haemolyticuraemic syndrome gave a positive reaction with the RotaScreen latex agglutination test in the absence of other evidence of rotavirus infection. When this test is performed on bloody specimens, positive reactions should be interpreted with caution and confirmed by other means. Clinical Microbiology and Public Health Laboratory, ...

A latex particle agglutination test is described which is suitable for the recognition of heat-labile enterotoxin-producing colonies of Escherichia coli immediately after primary culture on a variety of commonly used enteric diagnostic media. The test is simple and economical to perform, and the results are available in minutes.

A latex agglutination method for the rapid detection of beta-hemolytic streptococci from Lancefield serogroup C in throat swabs from 403 university students with symptomatic pharyngitis was evaluated. Compared with culture, the rapid test was poorly sensitive (34.4%) but very specific (98.4%) in detecting group C beta-hemolytic streptococci. The sensitivity of the rapid test improved with an in...

The exact nature of the "rheumatoid factor" is unknown, but it appears to be an antibody-like substance composed of a gamma globulin complex of high molecular weight. Two groups of tests have been used to detect it: the haemagglutination test and the latex-fixation or Bentonite flocculation test. In the first group the indicator consists of sheep red cells with rabbit anti-sheep haemolysin as t...