Luminescent oxygen channeling immunoassay: measurement of particle binding kinetics by chemiluminescence

  1. E F Ullman,
  2. H Kirakossian,
  3. S Singh,
  4. Z P Wu,
  5. B R Irvin,
  6. J S Pease,
  7. A C Switchenko,
  8. J D Irvine,
  9. A Dafforn, and
  10. C N Skold
  1. Research Department, Syva Company, Palo Alto, CA 94303.

Abstract

A method for monitoring formation of latex particle pairs by chemiluminescence is described. Molecular oxygen is excited by a photosensitizer and an antenna dye that are dissolved in one of the particles. 1 delta gO2 diffuses to the second particle and initiates a high quantum yield chemiluminescent reaction of an olefin that is dissolved in it. The efficiency of 1 delta gO2 transfer between particles is approximately 3.5%. The technique permits real-time measurement of particle binding kinetics. Second-order rate constants increase with the number of receptor binding sites on the particles and approach diffusion control. By using antibody-coated particles, a homogeneous immunoassay capable of detecting approximately 4 amol of thyroid-stimulating hormone in 12 min was demonstrated. Single molecules of analyte produce particle heterodimers that are detected even when no larger aggregates are formed.

« Previous | Next Article »Table of Contents

This Article

  1. PNAS June 7, 1994 vol. 91 no. 12 5426-5430
  1. » Abstract
  2. Full Text (PDF)

Classifications

About Our New Site Design >>
Link: Advanced Search

This Week's Issue

  1. August 19, 2008, 105 (33)
  1. Current Issue
  1. Alert me to new issues of PNAS

Most