ABSTRACT
This chapter focuses on microarrays, one of the latest technologies to be used in the parallel monitoring of gene expression, otherwise known as the field of genomics. Toxicogenomics describes the use of novel genomics techniques to investigate the adverse effects of exogenous agents.1 Alterations in messenger RNA (mRNA) levels are often the earliest detectable cellular events initiated in response to a potential toxin, hence the interest in developing techniques to measure differentially expressed genes via mRNA. The two main choices available to the potential user are to purchase microarrays from an external source or to fabricate them in-house. The former option has the advantage of reduced labor and capital investment. Microarrays are available from a variety of sources: commercial companies, service providers, or academic institutions. The first steps in creating a microarray are to decide upon the supporting matrix to be used and the source of the genes or DNA that will be arrayed.
