Painting of human chromosome 8 in fifteen minutes.

The technique of chromosome-in-situ suppression (CISS)-hybridization (chromosome painting) has now been well established. However, all standard protocols so far require long renaturation times (typically 12 hours and more). Here, we describe a new, extremely fast protocol for chromosome painting using a commercially available, directly fluorescence labelled probe for chromosome 8. The hybridization conditions used omit separate preannealing procedures and denaturing chemical agents. The renaturation time required for chromosome painting was reduced to 15 minutes. In addition, most washing steps were eliminated. As a consequence, the entire painting procedure was feasible in less than half an hour.