Mathematical Biology Seminar Alex Chagovetz, Electrical and Computer Engineering, University of Utah Wednesday November 26, 2008 3:05pm in LCB 215 "A Paradox of Multiplex DNA Melting onto Surfaces" Abstract: DNA melting analysis is a recognized methodology to study thermodynamics of DNA interactions and positively identify sequence-specific DNA targets in a multicomponent environment. Hybridization probes-based melting is widely used for genotyping of PCR amplified DNA. In several recent publications melting was also applied to analysis of microarray experiments to verify specificity of recognition by surface bound probes. All these approaches implicitly or explicitly assume that the multicomponent melts are superpositions of individual melts, i.e. that melting events in the multiplex environments are similar to single component melts. We demonstrate here that under certain conditions, i.e. when surface concentration of the probes is much less than solution concentrations of DNA targets, this assumption is not valid. Multi-target interactions on the sensing zone result in suppression of the lower affinity melting transitions, so that only the highest affinity melting transition is observed.