The study of genes is crucial to our understanding of the cell and its diseases. Combining robotics, chemistry, computer science, and biology, DNA microarrays allow us to study many points within a genome – which is composed of thousands of genes – at one time.
The microarray itself is a small support on which thousands of DNA sequences from different genes are attached at specific locations. One such support is a silicon wafer, just the size of a finger nail, embedded in a plastic case. Millions of DNA fragments, representing a portion of the human genome, are synthesized onto this wafer; an organism’s DNA is then loaded onto the microarray to be analyzed. Other types of supports are nylon membranes and glass microscope slides, and the DNA fragments – also called probes – can be synthesized, printed, or spotted onto these supports.