The utilization of DNA microarray is increasing in all areas of medical research as evidenced by the exponential increase in the number of publications on MedLine. Improvements in DNA microarray technology and the bioinformatic techniques for data analysis continue to take place and result in improved reliability, reproducibility, and volume of data. Replicate analysis remains important in order to allow statistical examination of significance. Expression of key genes should also be confirmed by alternative techniques. Single microarray experiments yield such vast amounts of data that shortage of manpower is the limiting factor to progression of full scientific discovery. Sharing of microarray data on the internet and its distribution to a broader scientific community will help overcome this manpower shortage. Currently, DNA microarray technology serves as a research tool. Ultimately, microarray technology may be used widely in the clinical setting as fingerprinting of cells, tissue, and disease states, though more targeted strategies using a limited repertoire of genes may be most valuable.