Protein (transcription factors and/or transcription cofactors)-binding to DNA is a critical event in regulation of transcription. Electrophoresis Mobility Shift Assay (EMSA), also known as gel shift assay, is a useful tool to detect protein- or protein complex-DNA/RNA interaction and to evaluate DNA binding specificity of transcription factors in vitro. Here we describe a simple method for EMSA with fluorescent dye-bound oligo DNA probes and recombinant protein expressed in bacterial cells. Using fluorescent dye instead of radioisotope enables easy handling and long-term storage of labelled-probes without reduction of detection sensitivity.