Combination of chromatographic and chemometric methods to study the interactions between DNA strands Original Research Article

This work describes the combination of size-exclusion chromatography and chemometric resolution methods to study the formation of complex DNA structures from individual strands. This combined procedure has been applied to two different experimental data. Firstly, the formation of an intermolecular Watson–Crick duplex structure formed by the individual unstructured strands. Secondly, the competition between the intermolecular Watson–Crick duplex and intramolecular quadruplex structures formed by two sequences found in the hTERT gene has been studied. The analysis of the recorded chromatograms at just one single wavelength may not always be enough to confirm the existence of a higher order structure. In these cases, recording the entire spectrum at each point of the chromatogram and applying appropriate chemometric resolution methods has shown to be a useful tool to resolve and quantify the contribution of all DNA structures to the analytical signal. In this work, the Multivariate Curve Resolution based on Alternating Least Squares (MCR-ALS) has been used to analyze the three-way data sets acquired along chromatographic runs.