Picoforce Measurements of Single DNA Interaction

Park Systems Inc 0 2010 DNA OligonucleotidesPicoforce Measurements of Single DNA Interaction Sample：DNA oligonucleotides Image Conditions：Force-distancemeasurement System Requirement： XE-100.SLD HeadSpring constantcalibration by thermaltune. Figure 1. The chemical attachment process of 50-mer DNA oligonucleotides involves self-assembledmonolayers (SAMs) of DNA-functionalized dendrons. The dendron used in this study was 9-anthrylmethylN-({[tris({2-[({tris-[(2-carboxyethoxy)methyl]methyl}amino)carbonyl]ethoxy}methyl)- Liquid probehand，Liquid Cell methyl]amino}carbonyl)propyl carbamate. Sample courtesy of Prof. J.W Park (Dept. of Chemistry，POSTECH) The Benefits Using force spectroscopy， interactions between single molecules can be observed bymonitoring the attractive or“jump-in”forces associated with molecular binding events.Molecular binding experiments presented by Jung et al.， (2007) were repeated using theXE-100 under the guidance of Prof. Park. With the oligonucleotide sequences immobilizedon the dendron-modified surface， the F-d curve shows association and dissociation of theDNA duplex. The force constant of the cantilever was calibrated in solution for everymeasurement by the thermal tune method， the variation of which is 12~15 pN/nm. The 2XE-seriesSAAFMprovides highly sensi-tive force-distance datato observe interactionsbetween single mole-cules through the low-noise control of the Zscanner movement. Theforce-distance resultsenable the assessmentof binding interactionsbetweensingleDNAmolecules， RNA mole-cules， and proteins. Figure 2. (A) A typical force-distance curve of the interaction between a DNA probe and the complementary50-mer DNA. (B) The histogram of unbinding forces acquired from the force-distance curves. The meanvalue of 64 pN with a narrow distribution shows that AFM can be a useful tool to study the interactionsbetween a single DNA molecule and other single DNA molecules， RNA molecules， and proteins. Park Systems Inc3040 Olcott StSanta Clara， CA 95054Tel： 408.986.1110Fax： 408.986.1199www.parkAFM.cominfo@parkAFM.com Relevant Publications Using the XE-AFM Journal： J. Am. Chem. Soc. 2007， 129 (30)，9349-9355. Title： Dendron Arrays for the Force-Based Detection of DNA Hybridization Events Authors： Yu Jin Jung， Bong Jin Hong， Wenke Zhang， Saul J. B. Tendler， Philip M. Williams， StephanieAllen， and Joon Won Park