alexa Light-scattering submicroscopic particles as highly fluorescent analogs and their use as tracer labels in clinical and biological applications.
Materials Science

Materials Science

Journal of Nanomedicine & Nanotechnology

Author(s): Yguerabide J, Yguerabide EE

Abstract Share this page

Abstract Submicroscopic gold particle suspensions scatter colored light when illuminated with white light, and we have observed that a light-scattering gold particle suspension has the same appearance as a fluorescing solution. Thus, when illuminated by a narrow beam of white light, a 40-nm gold sol displays a clear (not cloudy), green scattered light (Tyndall) beam and has the same appearance as a fluorescing fluorescein solution. These, as well as other, observations have suggested to us that, in general, light-scattering particles can be treated as fluorescent analogs and used as fluorescent analog tracers in immuno- and DNA probe assays as well as in cell and molecular biology studies. Light-scattering particles are advantageous in these applications because particles such as gold and silver have very high light-scattering powers, which allows these particles to be easily detected, by light-scattering, at particle concentrations as low as 10(-16) M. The scattered light can be detected by the unaided eye for qualitative measurements or with a simple light-sensitive detector for quantitative measurements. Moreover, individual particles can be easily detected by eye or a video camera using a simple light microscope with a proper illuminating system. In addition, submicroscopic particles which scatter blue, green, yellow, orange, or red light can be readily synthesized. Antibodies, DNA probes, and other tracer substances can be readily attached to gold and other particles without altering their light-scattering properties. In this article we present the theory which allows one to predict the light-scattering properties of particles of different sizes and compositions and identify those particle sizes and compositions which appear most adequate for particular applications. Furthermore, we calculate molar extinction coefficients and emission efficiencies for particles of different sizes and compositions which allows us to compare the light-producing powers of these particles with those of well known fluorescent tracers. A 60-nm gold particle, for example, is equivalent to about 3 x 10(5) fluorescein molecules. Very simple, easy to use, low-cost, ultrasensitive immuno- and DNA probe assays can be developed using light-scattering particles as fluorescent analog tracers. Single particles can be detected on cell surfaces and inside cells using light microscopy techniques with proper illumination as described in the article. At high particle densities, particle-labeled cells have the same appearance as fluorescent cells. Copyright 1998 Academic Press.
This article was published in Anal Biochem and referenced in Journal of Nanomedicine & Nanotechnology

Relevant Expert PPTs

Recommended Conferences

  • Nano Congress for Next Generation
    August 31-September 01, 2017 Brussels,Belgium
  • Graphene & 2D Materials
    September 14-15, 2017 Edinburgh, Scotland
  • Graphene & 2D Materials
    November 6-7, 2017 Frankfurt, Germany
  • World Congress on Nanoscience and Nano Technology
    October 16-17, 2017 Dubai, UAE
  • World Medical Nanotechnology Congress
    October 18-19, 2017 Osaka, Japan
  • Nanoscienceand Molecular Nanotechnology
    Nov 06-08, 2017 Frankfurt, Germany
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version