Near-infrared fluorescence EMSA offers a safe, sensitive alternative to radioactive EMSA techniques.
Figure 1. AP-1 EMSA using IRDye 700 AP-1 oligonucleotide duplex. Nuclear extracts of HeLa cells treated with serum, were used to visualize increased AP-1 binding after serum stimulation. Competition reactions contained 100-fold molar excess of unlabeled oligo duplex. Arrow indicates mobility shift of fluorescent oligos. Asterisk indicates reduction of mobility shift caused by an excess of unlabeled competitor DNA. Wet gel was imaged with Odyssey Classic Infrared Imager.
Figure 2. EMSA/gel shift assay. IRDye 700 EMSA performed with consensus oligos for 3 different transcription factor targets. Arrows indicate positions of mobility shift.