DNA microarrays: Boundless technology or bound by technology? Guidelines for studies using microarray technology

The biotechnology revolution has led to unpre- cedented progress in elucidating the structure of the human genome and determining patterns of gene ex- pression relevant to disease pathogenesis. Each new breakthrough produces an immediate and often intense flurry of activity as investigators explore its place in the scientific repertoire and determine the insights it pro- vides for understanding disease. Polymerase chain reac- tion (PCR) is an example of such a transforming tech- nology which, in a short time, facilitated a quantum leap in our ability to clone novel genes and quantify gene expression at the level of messenger RNA (mRNA). As with all "hot" new methods, many years passed before the strengths and weaknesses of PCR were recognized and more powerful applications, such as real-time PCR, were developed and refined. Microarray technology represents another cutting-edge technology that promises extraordinary ad- vances in the study of disease. As described in an article by Grant et al in this issue of Arthritis & Rheumatism (1), microarray technology provides scientists the tools to scan simultaneously the array of expressed genes in a cell and glean myrid information about cellular function. In the face of such power and precision, it may appear as if hypotheses are superfluous to the pursuit of research and that specific questions need no longer be asked. Indeed, microarray technology, buttressed by elaborate computer software of great sophistication, can give the illusion that all of the information can be "downloaded" from the cell and its secrets revealed to the inquisitive mind. The siren song of microarrays is indeed strong and tantalizing.