9-Ethylguanine is primarily utilized in biochemical research, particularly in studies related to DNA repair mechanisms and mutagenesis. It serves as a modified nucleobase, allowing scientists to investigate how alterations in DNA structure affect cellular processes and genetic stability. This compound is often used to mimic damaged guanine in DNA, providing insights into the efficiency and accuracy of DNA repair enzymes. Additionally, it plays a role in understanding the impact of alkylating agents on DNA, which is crucial for developing targeted cancer therapies. Its applications extend to studying the biochemical pathways involved in nucleotide excision repair and base excision repair, contributing to advancements in molecular biology and oncology research.