Researchers interested in evaluating the interaction of transcription factors with their target sequences commonly employ the electrophoretic mobility shift assay, more commonly known as the "gel-shift." Gel-shift assays can provide crucial information on the binding of transcription factors to their consensus sequences, but because the technique relies on the use of radiolabeled nucleotides, it can be cumbersome and time-consuming. A single gel-shift assay can take days to complete, and in the

Protein-protein interaction is a key concept in the fields of signal transduction and gene regulation. Investigators can make educated guesses as to whether two proteins actually interact, but verifying these interactions is not a trivial task. Classical biochemical techniques are fraught with pitfalls that make data acquisition and interpretation difficult. BioSignal Packard, a division of Packard Instruments, has introduced the BRET2 (Bioluminescence Resonance Energy Transfer) system to assess