chapter  18
6 Pages

Pathway-Specific cDNA Array Using Luminescent Detection

A variety of conventional methods exist to profile the expression of genes. Assays such as reverse transcription polymerase chain reaction (RT-PCR), Northern blot, and RNAse protection assay are generally concerned with one or several genes. At the other extreme, large-scale gene screens measure thousands of genes in an array on a single glass chip. The materials and instrumentation used in such systems are expensive. The high-density arrays, which are often constructed from whole plasmids or amplified inserts, can allow high levels of cross-hybridization. The use of oligo-dT

or random primers can result in low sensitivity due to inefficient cDNA probe synthesis. Even when using gene-specific primers, sensitivity can be low because of the complexity of the primer mix required for reverse transcription of mRNA. Not surprisingly, the analysis and confirmation of these results can be time-consuming and disappointing. The GeArray

represents a middle ground: an inexpensive method that offers high sensitivity in detecting multiple genes within a specific pathway.