UNIT 13.5 BeadCons: Detection of Nucleic Acid Sequences by Flow Cytometry

  1. Douglas Horejsh,
  2. Federico Martini,
  3. Maria Rosaria Capobianchi

Published Online: 1 NOV 2005

DOI: 10.1002/0471142956.cy1305s34

Current Protocols in Cytometry

Current Protocols in Cytometry

How to Cite

Horejsh, D., Martini, F. and Capobianchi, M. R. 2005. BeadCons: Detection of Nucleic Acid Sequences by Flow Cytometry. Current Protocols in Cytometry. 34:13.5:13.5.1–13.5.13.

Author Information

  1. National Institute for Infectious Diseases “L. Spallazani”-IRCSS, Rome, Italy

Publication History

  1. Published Online: 1 NOV 2005
  2. Published Print: OCT 2005


Molecular beacons are single-stranded nucleic acid structures with a terminal fluorophore and a distal, terminal quencher. These molecules are typically used in real-time PCR assays, but have also been conjugated with solid matrices. This unit describes protocols related to molecular beacon–conjugated beads (BeadCons), whose specific hybridization with complementary target sequences can be resolved by cytometry. Assay sensitivity is achieved through the concentration of fluorescence signal on discrete particles. By using molecular beacons with different fluorophores and microspheres of different sizes, it is possible to construct a fluid array system with each bead corresponding to a specific target nucleic acid. Methods are presented for the design, construction, and use of BeadCons for the specific, multiplexed detection of unlabeled nucleic acids in solution. The use of bead-based detection methods will likely lead to the design of new multiplex molecular diagnostic tools.


  • BeadCons;
  • molecular beacons;
  • microspheres;
  • flow cytometry;
  • differential diagnosis