DETECTION OF FLUORESCENCE IN-SITU HYBRIDIZATION ON HUMAN METAPHASE CHROMOSOMES BY NEAR-FIELD SCANNING OPTICAL MICROSCOPY

Fluorescence in situ hybridization signals on human metaphase chromoso mes are detected by a near-field scanning optical microscope. This mak es it possible to localize and identify several fluorescently labeled genomic DNA fragments on a single chromosome with a resolution superio r to traditional fluorescence microscopy. Several nucleic acid probes have been used. The hybridization signals are well resolved in the nea r-field fluorescence images, and the exact location of the probes can be correlated to the topography as it is afforded by the shear-force f eedback.