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Methods for labeling DNA and protein molecules with various colorful (and not-so-colorful) tags


COLD SPRING HARBOR, N.Y. (Tues., May 1, 2007) – Physical alterations of DNA in chromosomes can cause serious diseases such as Down syndrome, Prader-Willi syndrome, or cancer. Likewise, changes to the physiological environment of cells—with drugs or toxins, for example—can alter their metabolic output. To track these processes, scientists need ways to mark genes and their protein products. This month’s release of Cold Spring Harbor Protocols (www.cshprotocols.org) features freely available methods for marking molecules to identify gene alterations and metabolic shifts.

The first method (www.cshprotocols.org/cgi/content/full/2007/10/pdb.prot4743 ) describes how to grow cells from bacteria, yeast, insects, or mammals in media containing the stable isotope nitrogen-15. As the cells grow, they produce nascent proteins that include nitrogen-15, a marker that distinguishes newly formed metabolic products from pre-existing ones. The differences between these cells and “normal” cells (grown in media without nitrogen-15) can then be quantified using a technique called mass spectrometry.

To identify structural features and abnormalities in chromosomes, scientists need to tag DNA probes with visual markers. The second freely available method (www.cshprotocols.org/cgi/content/full/2007/10/pdb.prot4730 ) describes how to label DNA probes with fluorescent markers of six different colors, which span the visible spectrum. These labeled DNA probes can be used simultaneously in FISH (fluorescent in situ hybridization) experiments, during which the probes bind to specific chromosomal regions of interest. The colorful chromosomes can then be viewed under a microscope.

Cold Spring Harbor Protocols (www.cshprotocols.org) is an online resource of methods used in a wide range of biology laboratories. It is structured to be highly interactive, with each protocol cross-linked to related methods, descriptive information panels, and illustrative material to maximize the total information available to investigators. Each protocol is clearly presented and designed for easy use at the bench—complete with reagents, equipment, and recipe lists. Life science researchers can access the entire collection via institutional site licenses, and can add their suggestions and comments to further refine the techniques.

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For content and submission information:
David Crotty (crotty@cshl.edu;516-422-4007), Executive Editor, Cold Spring Harbor Protocols

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Wayne Manos (manos@cshl.edu;516-422-4009), Director, Serials Marketing, CSHL Press

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