Particle counting immunoassay for urinary cotinine. Comparison with chromatography, enzyme-linked immunoassay and fluorescence polarization immunoassay.
Urinary cotinine was measured according to its inhibitory activity on the agglutination of cotinine-coated latex particles by anti-cotinine antibodies, the agglutination being measured by optical counting of the remaining non-agglutinated particles (particle counting, PaC). The detection limit was 0.03 microgram/ml and the practical range extended from 0.03 to 3.9 micrograms/ml. The correlation results of 320 urine samples with those of high pressure liquid chromatography, enzyme-linked (Coti-Tracq EIA, Serex Inc., Maywood, NJ, USA), and fluorescence polarization immunoassay (TDX instrument, Abbott, Abbott Park, IL, USA) were r = 0.90, r = 0.69, r = 0.87, respectively, whereas the correlation coefficients between the assays other than particle counting ranged from 0.62 to 0.88. PaC does not require any separation step and can thus be easily automated.
Galanti
L M
LM
Clinical Laboratory, University Hospital of Mont-Godinne, Yvoir, Belgium. galanti@mexp.ucl.ac.be
Dell'Omo
J
J
Vanbeckbergen
D
D
Dubois
P
P
Masson
P L
PL
Cambiaso
C L
CL
D002851:Chromatography, High Pressure Liquid; D003367:Cotinine / Q000652:urine*; D004797:Enzyme-Linked Immunosorbent Assay; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007841:Latex Fixation Tests; D012907:Smoking / Q000652:urine
D003367:Cotinine