Calibration beads containing luminescent lanthanide ion complexes

J Biomed Opt. 2009 Mar-Apr;14(2):024022. doi: 10.1117/1.3103646.

Abstract

The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, would be enhanced by the availability of narrowband emitting, UV excited lanthanide calibration beads. 0.5-, 3-, and 5-microm beads containing a luminescent europium-complex are manufactured. The luminescence distribution of the 5-microm beads is measured with a time-delayed light-scatter-gated luminescence flow cytometer to have a 7.0% coefficient of variation (CV) The spacial distribution of the europium-complex in individual beads is determined to be homogeneous by confocal microscopy. Emission peaks are found at 592, 616 (width 9.9 nm), and 685 nm with a PARISS spectrophotometer. The kinetics of the luminescence bleaching caused by UV irradiation of the 0.5- and 5-microm beads measured under LED excitation with a fluorescence microscope indicate that bleaching does not interfere with their imaging. The luminescence lifetimes in water and air were 340 and 460 micros, respectively. Thus, these 5-microm beads can be used for spectral calibration of microscopes equipped with a spectrograph, as test particles for time-delayed luminescence flow cytometers, and possibly as labels for macromolecules and cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calibration
  • Flow Cytometry / standards*
  • Lanthanoid Series Elements / analysis*
  • Lanthanoid Series Elements / chemistry*
  • Luminescent Measurements / standards*
  • Microscopy, Fluorescence / standards*
  • Microspheres
  • Spectrometry, Fluorescence / standards*

Substances

  • Lanthanoid Series Elements