Rissin et al. increase the sensitivity of sandwich ELISA by segregating beads bearing a single enzyme-labeled immunoconjugate into femtoliter-volume reaction chambers. As the small volume of each well permits detection of extremely low levels of fluorescence, protein abundance is determined by counting the number of fluorescent wells as a percentage of the number of wells containing beads.
- David M Rissin
- Cheuk W Kan
- David C Duffy