Detecting Cancer

Resembling a stained-glass window, this glowing microarray display actually demonstrates how scientists analyze the activity of genes in certain types of cells.

Used to compare thousands of genes at once, the microarray is a universal tool that has launched genomic research into the fast lane. Microarrays enable faster tracking of disease-causing genes, development of new drugs, and analysis of how genes direct cell functions.

Studying Breast Cancer

The human genes dotted on the surface of this microarray will glow if they are active in the cell. The brighter the color, the more active the gene. If the genes are inactive, they will not light up.

This large-scale microarray represents part of an actual DNA chip used to study genetic mutations that can lead to breast cancer. The real chip holds 8,102 genes; the portion depicted here shows 576 squares, each with a gene sequence.

Here, a healthy breast cell is compared to a cancerous breast cell. By finding genes that are active only in cancerous cells, scientists can discover new ways to treat cancer.

Hunting for Genes

Faced with the "needle-in-a-haystack" scenario, researchers developed microarrays to sift through the genome. By looking at RNA—a form of the genetic code that exists only when a gene is active—scientists can see if genes are switched on or off.

A mechanized dropper precisely dots known gene sequences along the surface of a glass microarray chip.
Researchers color-code a cell's active genes based on the RNA found in the cell.
Color-coded genes are smeared onto the surface of the chip.
The color-coded genes stick to the chip, matching the known genes already on the chip surface.
The chip glows where the genes match, illuminating the colors of the active genes.
A computerized chip reader scans the microarray to identify the glowing genes.