title: Enzyme-linked immunosorbent assay of nicotine metabolites.
abstract: BACKGROUND
  The level of cotinine in biological specimens, such as serum, urine, and saliva, measured by gas or liquid chromatography is the most validated and reliable indicator of exposure to tobacco smoke. However, chromatographic methods are not always suitable for all types of situations.
  
  
  METHODS
  We validated a commercially available enzyme-linked immunosorbent assay (ELISA) that uses a polyclonal antibody to cotinine as a practical alternative to chromatographic methods.
  
  
  RESULTS
  The cotinine antibody cross-reacts to 3-hydroxycotinine (3HC) and its glucuronide, thus generating a value for immunoreactive (IR) cotinine, which is a complex comprising cotinine, 3HC, and 3HC-glucuronide. The levels of IR cotinine in the urine of kindergarten children closely correlated with those of cotinine measured by gas chromatography-mass spectrometry (GC-MS) and reflected the smoking behavior of their parents more precisely than cotinine levels determined by GC-MS.
  
  
  CONCLUSIONS
  Our findings showed that the cotinine-based ELISA can be a practical biomarker of exposure to tobacco smoke.
authors: Department of Pharmaceutical Science, School of Pharmacology, Colorado University, Aurora, CO 80045, USA. Akiko.Matsumoto@ucdenver.edu
authors: Akiko
authors: A
authors: Matsumoto
authors: Toshihiro
authors: T
authors: Ino
authors: Mitsuhiro
authors: M
authors: Ohta
authors: Tetsuya
authors: T
authors: Otani
authors: Sachiko
authors: S
authors: Hanada
authors: Atsushi
authors: A
authors: Sakuraoka
authors: Akane
authors: A
authors: Matsumoto
authors: Masayoshi
authors: M
authors: Ichiba
authors: Megumi
authors: M
authors: Hara