Studies on the detection of nucleotides and oligonucleotides by mass spectrometry

The long-term goal of this project is to develop novel methods for the detection of nucleotides, oligonucleotides, and modified nucleotides such as DNA adducts by mass spectrometry. DNA adducts are important because they are formed during chemical carcinogenesis as well as during anti-cancer chemotherapy. However, DNA adducts are not routinely monitored due to difficulties associated with their detection. Mass spectrometry is a promising method for the detection of DNA adducts because it can detect almost any type of adduct, and in addition mass spectrometers can provide structural information. The work presented here shows successful detection of nucleotides and oligonucleotides of various sizes. Specific sizes detected include mononucleotides, 6-mer, 8-mer, 1 O-rner, and 16-mer oligonucleotides, and enzyme digests of genomic DNA and oligonucleotides. Through researchinvolving several separation methods (HPLC, TLC, and PAGE) and alternative detection methods (32P postlabeling and mass spectrometry), a novel method for the separation and detection of DNA adducts has been developed. The present research has shown promising results for tracking nucleotides in TLC using biomimetic dyes in order to eliminate the need for radioactive isotopes. In addition, progress has been made involving elution of nucleotides from a TLC plate and subsequent detection of these nucleotides by mass spectrometry. Together, these results will facilitate future studies that involve testing samples that contain altered DNA by different mass spectrometers, which are expected to be particularly useful for the detection and identification of mixed or novel DNA \u27 modifications