Differential display (DD) is a method used worldwide for identifying differentially expressed genes in eukaryotic cells. The mRNA DD technology works by systematic amplification of the 3′ terminal regions of mRNAs. Using anchored primers designed to bind 5′ boundary of the polyA tails for reverse transcription, followed by polymerase chain reaction (PCR) amplification with additional upstream primers of arbitrary sequences, mRNA subpopulations are separated by denaturing polyacrylamide electrophoresis. This allows direct side-by-side comparison of most of the mRNAs between or among related cells. Because of its simplicity, sensitivity, and reproducibility, the mRNA DD method is finding wide-ranging and rapid applications in developmental biology, cancer research, neuroscience, pathology, endocrinology, plant physiology, and many other areas. Since the recent development of the fluorescent differential display (FDD), the first nonradioactive DD system with equivalent sensitivity to the original 33 P isotopic labeling method, it is now possible with this technology to automate, which can greatly increase the throughput and accuracy of mRNA DD.
