Microarrays allow for the tracking of thousands of molecular reactions on a small microscopic slide. The chips can be designed to detect specific genes or measure gene activity; this is called expression analysis where the chip contains all the possible genes. Future use of these chips would be to decide the best treatment for a patient which leads into the pharmacogenomic section. The chips can also map out the human genome based on single nucleotide polymorphisms. Therefore, instead of all possible genes, you make a chip with many variations of one gene. Then, you take a DNA sample, conduct PCR, and the spot lit up on the microarray will correspond to a particular sequence. Again this can be employed to test different drugs and their reactions.

Look at Diagram below for diagram and procedure.