Human Genome Project and the Gene Chip

Mapping the human genome

In 1973, Victor McKusick teamed up with Yale geneticist Frank Ruddle to launch a biannual series of workshops dedicated to updating the human gene map. In the 1970s and 1980s, technological advances suggested it might be possible to map the entire set of human genes. A gene mapping and sequencing project was begun with federal funding in 1988, the Human Genome Project.

The goals of the Human Genome Project are to sequence all the DNA of the human chromosome set, to map the location of every gene, and to make the information widely available by the year 2005. Since the founding of the project, other governments worldwide and private companies have joined the effort, racing to sequence the human genome faster and to reap the profits.

"It seems almost a miracle to me that 50 years ago, we could have been so ignorant of the genetic material, and now we can imagine that we will have the complete genetic blueprint of man," said James Watson.

Here, a chemical tag glows red, indicating the location of a gene on chromosome 11.

Technology may speed gene testing

A microscopic carpet of thousands of synthetic DNA strands covers the fingernail-size square of glass in this cartridge. Each type of strand was custom-designed to recognize genes with a particular sequence.

A gene chip can measure the activity of thousands of genes at a time. Gene chip applications include pinpointing mutations and measuring the expression of specific genes in particular cells and tissues. Gene chips now in development detect mutations in the p53 gene, associated with a cellŐs tendency to become cancerous. Manufacturers like Affymetrix, the maker of this chip, collaborate with scientists to develop potential uses for it.

To perform a test, researchers inject genetic material into the cartridge. A fluorescent glow, read by a computer, indicates where the probes match fragments of the tested gene sequences.

This colorful digitized readout is crammed with data. Patterns of brightness are analyzed to detect where synthetic DNA probes match the tested genes.