Applications of nylon membrane arrays to gene expression analysis

Gene expression analyses by hybridization of probes derived from mRNA to cDNA targets arrayed on a nylon membranes have been performed with increasing frequency and success over the last decade. While the initial costs of generating arrays are moderately high, they are now available commercially as complete packages which include the membranes and associated image analysis software for acquisition and processing of the data. Arrays can be used to generate information concerning the expression of mRNA from cells treated with various agents or from different tissues, e.g. comparing diseased with normal controls. To date, many groups, including immunologists, have used this technology to examine gene expression within their area of biological interest. The main characteristic of these systems is the large amount of data generated, since the expression of many thousands of genes are measured in parallel. The main practical issues are sensitivity of detection, reproducibility, comparability with other systems (e.g. Northern blots) and processing of data. Some of the significant applications of nylon array technology to date are reviewed in this chapter, and with these issues in mind, we include a discussion of our own experiences in this area.