An easy and reliable procedure of microdissection technique for the analysis of chromosomal breakpoints and marker chromosomes

Microdissection in combination with reverse painting fluorescence in-situ h ybridization (FISH) is a very effective method to identify breakpoints and rearrangements of derived chromosomes and reveal the chromosomal origin of marker chromosomes. We describe an innovation that allows a convenient, fas t and safe isolation of microdissected fragments as currently available pro tocols. The microdissected chromosomes are harvested in a collection drop l ocated in a movable micropipette adjusted to a second micromanipulator unde r microscopic observation. We used this technique to analyze several cytoge netic aberrations. In order to evaluate the efficiency of our microdissecti on procedure, we compared the results obtained with microdissection probes made from only one fragment with those obtained with more than six microdis sected fragments. In all cases, the single- fragment microdissections were sufficient to provide probes.