Abstract

Probing the Physical Limits of DNA Affinity Sensors

Jef Hooyberghs, Project Manager, Flemish Institute for Technological Research

In biosensor technologies which aim to detect and identify nucleic acid molecules, hybridization is often the basic process. For the detection one can use labels or measure changes in surface properties, and a wide variety of biosensor techniques is available for this purpose. However, the underlying hybridization process is in principle universal. Despite the importance of the hybridization process, experimental design and data analysis are seldom based on the underlying mechanisms. We have studied over the past years physicochemical aspects of DNA hybridization in a biosensor context, with a focus on the thermodynamics of mismatches, non-Watson-Crick pairing. Due to a need for high parallelization the applied methodology is DNA adsorption in microarray technology.The results comprise-physics of DNA hybridization: non-equilibrium effects, interaction of mismatches, impact of probe length enzyme free mutation identification: two case studies on clinical samples (HIV and KRAS oncogene) show the flexibility for point mutation applications with a good limit of detection dynamic range extension of hybridization sensors: the use of thermodynamics of probes with different affinity allows to increase the dynamic range of any hybridization sensor without the need to adjust hardware.