Abstract

Fluorescence resonance energy transfer (FRET) [1] is a standard spectroscopic technique for measuring distances in the 10-75 Å range. We extended the technique’s sensitivity by measuring energy transfer between a single donor fluorophore and a single acceptor fluorophore. The Near field scanning optical microscopy (NSOM) [2] was used to obtain simultaneous dual color imaging and emission spectra from a single pair of donor and acceptor fluorophores linked by a short (10 or 20 bases long) DNA molecule. The DNA was dried on amino-propyl-silanized glass. Near field fluorescence images [3] and emission spectra [4] were taken on single DNA molecules labeled with donor only, with acceptor only, or with both donor and acceptor.

© 1996 Optical Society of America