Fluorescence polarization immunoassay: detection of antibody to Brucella abortus.
Fluorescence polarization immunoassay (FPA) is a homogeneous immunoassay useful for rapid and accurate detection of antibody or antigen. The principle of the assay is that a fluorescent dye (attached to an antigen or an antibody fragment) can be excited by plane-polarized light at the appropriate wavelength. As a rule, a small molecule rotates faster when in solution than a larger molecule. The rotation rate may be assessed by measuring light intensity in the vertical and horizontal planes. Generally, the time it takes a molecule to rotate through a given angle is an indication of its size. When a small molecule that rotates rapidly is bound to a larger molecule, the rotation rate is decreased and this decrease is measured. Because it is a primary antigen-antibody interaction, the rate of reaction is very rapid and usually a result may be obtained in minutes. This technology was applied to the detection of antibody to Brucella abortus in serum and milk, providing for the first time a rapid primary binding assay that is cost effective for use in the field.
Nielsen
K
K
Canadian Food Inspection Agency, Animal Diseases Research Institute, 3851 Fallowfield Road, Nepean, Ontario, K2H 8P9, Canada. nielsen@em.agr.ca
Lin
M
M
Gall
D
D
Jolley
M
M
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis* / Q000097:blood / Q000276:immunology*; D002003:Brucella abortus / Q000276:immunology*; D002006:Brucellosis / Q000097:blood / Q000276:immunology / Q000382:microbiology; D002417:Cattle; D002852:Chromatography, Ion Exchange; D005452:Fluoresceins / Q000737:chemistry / Q000378:metabolism; D005454:Fluorescence Polarization / Q000295:instrumentation / Q000379:methods; D016231:Fluorescence Polarization Immunoassay / Q000295:instrumentation / Q000379:methods*; D008892:Milk / Q000737:chemistry / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D012680:Sensitivity and Specificity
D000907:Antibodies, Bacterial; D005452:Fluoresceins; D011135:Polysaccharides, Bacterial