Detection and comparison of protein-DNA interactions using DNA-BIND plate and horseradish peroxidase-based...

We describe a procedure for detection and comparison of protein-DNA interactions using DNA-BIND plate and horseradish peroxidase (HRP)-based colorimetric assay. Amino-modified oligonucleotide was covalently immobilized on the surface of DNA-BIND plate. After the complementary oligonucleotide was annealed, the plate was incubated with protein to allow sequence-specific DNA binding. Primary antibody and HRP-labeled secondary antibody were then employed, and colorimetric assay was conducted before the absorbance was read. This is a sensitive, specific, and high-throughput method that has been applied not only in the detection of protein-DNA interaction but also in the quantitative comparison of DNA-binding capabilities among wild-type and mutant proteins.