National Center for Human Genome Research other research news

A report in Science describes chromosome painting with fluorescent labels in color combinations that allow distinct signals from each of the 24 chromosomes in human cells. The spectral karyotyping found aberrations, with the smallest a translocation unrecognized by conventional means. The limit of sensitivity appears to be 500-1500 kbp. A breast cell cancer line, previously determined to have multiple chromosome rearrangements, also was appropriately karyotyped by the method.

The coloring method is a variant of existing FISH (fluorescent in-situ hybridization), and chromosome painting techniques, in which markers are added to pieces of DNA that bind to sites along the chromosomes. Here, using nucleotides linked to five different fluorophores, the researchers generated enough different shades to uniquely color each chromosome with its own distinct hue. The detection method combined Fourier spectroscopy, charge-coupled device imaging, and optical microscopy. ...