Particle counting immunoassay for urinary cotinine. Comparison with chromatography, enzyme-linked immunoassay and fluorescence polarization immunoassay

Clin Chem Lab Med. 1999 Jul;37(7):729-34. doi: 10.1515/CCLM.1999.112.


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.

Publication types

  • Comparative Study

MeSH terms

  • Chromatography, High Pressure Liquid
  • Cotinine / urine*
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescence Polarization Immunoassay
  • Humans
  • Immunoassay / methods*
  • Latex Fixation Tests
  • Smoking / urine


  • Cotinine