Microarray technology now allows us to look at many genes at once and determine which are expressed in a particular cell type. DNA molecules representing many genes are placed in discrete spots on a microscope slide. This is called a microarray, also known as gene chip, DNA chip or biochip. Several applications of microarrays make use of SNP detection, including Genotyping, forensic analysis and identifying drug candidates and predisposition to disease.
Researchers are using this technology to learn which genes are turned off or on in human tissues. Genes that are expressed differently in the two tissues may be involved in causing disease.