Increased sensitivity of diagnostic latex agglutination tests in an ultrasonic standing wave field.
A technique is described which increases the sensitivity of latex agglutination tests for soluble and particulate antigens. The levels of detection of tests for C-reactive protein and E. coli O157 respectively have been improved by x256 and x1024 compared with the standard test procedure of sample rotation on a test-card. This new method combines dilution of the test latex particles, a 2 min sample treatment in the ultrasonic standing wave field of a tubular piezo-electric transducer and subsequent examination by video-microscopy. Ultrasonic treatment is required to achieve increased localised concentrations of the latex particles in the standing wave field, and dilution of the latex is a critical requirement to allow agglutination to occur at low antigen concentrations.
Grundy
M A
MA
School of Pure and Applied Biology, University of Wales College Cardiff, UK.
Moore
K
K
Coakley
W T
WT
D000942:Antigens, Bacterial / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis; D004926:Escherichia coli / Q000276:immunology; D007841:Latex Fixation Tests / Q000379:methods*; D008853:Microscopy / Q000379:methods; D012680:Sensitivity and Specificity; D014465:Ultrasonics
D000942:Antigens, Bacterial; D002097:C-Reactive Protein