β-Ethoxy-α-ketobutyraldehyde is a chemical probe that specifically modifies the N1 and N2 sites of guanine. It is primarily utilized to study the spatial protection of single-stranded/double-stranded regions of nucleic acids and protein binding sites. Additionally, β-Ethoxy-α-ketobutyraldehyde is employed in nucleic acid structure analysis and footprinting studies of protein-nucleic acid complexes.