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

Fluorescence in situ hybridization on human metaphase chromosomes is d etected by near-field scanning optical microscopy. This combination of cytochemical and scanning probe techniques enables the localization a nd identification of several fluorescently labelled genomic DNA fragme nts on a single chromosome with an unprecedented resolution. Three nuc leic acid probes are used: pUC1.77, p1-79 and the plasmid probe alpha- spectrin. The hybridization signals are very well resolved in the near -field fluorescence images, while the exact location of the probes can be correlated accurately with the chromosome topography as afforded b y the shear force image.