Sponsored by the U.S. Department of Energy Human Genome Program
Human Genome News Archive Edition
Human Genome News, January 1992; 3(5)
Lawrence Livermore National Laboratory (LLNL) announced in October that chromosome painting, a new staining technology with the potential to improve dramatically the diagnosis of many cancers, has been transferred to Imagenetics, a medical diagnostics company based in Naperville, Illinois. LLNL officials see this as one of the laboratory's most important technology transfers to the private sector.
The key discovery, made by an LLNL biomedical team led by Joe Gray and Dan Pinkel, is that very complex DNA probes can be used for fluorescently staining the entire length of any specific chromosome. Different chromosomes in the same cell can be made to fluoresce different colors, a technique that makes chromosome abnormalities such as translocations easy to see. A translocation occurs when a piece of one chromosome is exchanged with a piece of another; in chronic myelo-geneous leukemia, for example, pieces of chromosomes 9 and 22 are exchanged. Chromosome painting is particularly effective in metaphase when the chromosomes are condensed and easily visible as distinct objects in a microscope.
With conventional techniques, says Robert Jenkins (Mayo Clinic), "Sometimes analysis is much more difficult because parts of one chromosome will look like a natural part of another chromosome. But with the paints, the fluorescent dyes light up the different chromosomes in two distinct colors, showing the translocation."
Imagenetics research led to development of methods that permit at least five different chromosomes to be analyzed at once. Commercial availability will make the paints much cheaper to most researchers, who will not have to grow and label the DNA in their laboratories. Thus the number of investigators using the probes will be expanded, and research progress will be speeded up.
Researchers hope that improved detection of chromosome abnormalities will assist in better understanding the multiple genetic changes involved in the development and progression of cancer and may eventually permit treatment to be tailored to specific abnormalities present in particular tumors. To further their research and explore its medical value, Gray, Pinkel, and their team moved in July 1991 from LLNL to the University of California, San Francisco.
Chromosome painting has also proven valuable in detecting chromosome translocations caused by exposure to radiation and chemicals. This feature may help determine cumulative lifetime exposure doses and allow estimation of health risks.
Under a 1989 funding and licensing agreement, Whole Chromosome Paints(TM) has become a product line of Imagenetics and will be sold worldwide by Life Technologies, Inc., through the GIBCO BRL brand as WCP(TM) DNA Probes. Of 24 paints, 9 became available in October and the remaining 15 should be out in 6 to 12 months, according to Imagenetics' Tom Mozer.
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Human Genome Program, U.S. Department of Energy, Human Genome News (v3n5).
The Human Genome Project (HGP) was an international 13-year effort, 1990 to 2003. Primary goals were to discover the complete set of human genes and make them accessible for further biological study, and determine the complete sequence of DNA bases in the human genome. See Timeline for more HGP history.
Published from 1989 until 2002, this newsletter facilitated HGP communication, helped prevent duplication of research effort, and informed persons interested in genome research.