Enhanced emission of highly labeled DNA oligomers near silver metallic surfaces.
Fluorescein is a widely used fluorescent probe in DNA analysis. One difficulty with fluorescein is its self-quenching due to resonance energy transfer between the residues, which results in decreased intensities with increasing labeling density. We examined the emission spectral properties of DNA oligomers labeled with one or five fluorescein residues. The emission intensity of the more highly labeled oligomer was decreased due to self-quenching. The self-quenching was mostly eliminated when this oligomer was held approximately 90 A from the surface of metallic silver particles. The intensities increased 7- and 19-fold for the oligomers with one or five fluoresceins, respectively. The increased intensity did not result in increased photobleaching. These results suggest the use of substrates coated with silver particles for increased sensitivity on DNA arrays or for DNA analysis.
Malicka
Joanna
J
Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201, USA.
Gryczynski
Ignacy
I
Lakowicz
Joseph R
JR
D000818:Animals; D001360:Avidin / Q000737:chemistry; D001483:Base Sequence; D001710:Biotin / Q000737:chemistry; D002417:Cattle; D004247:DNA / Q000032:analysis* / Q000378:metabolism*; D019793:Fluorescein / Q000737:chemistry; D015394:Molecular Structure; D010777:Photochemistry; D012709:Serum Albumin / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods
D012709:Serum Albumin; D001360:Avidin; D012834:Silver; D001710:Biotin; D004247:DNA; D019793:Fluorescein