Single Molecule Bio-PhysicsSingle Molecule Fluorescence TechniquesSingle Molecule Fluorescence TechniquesState of the Art imaging of single (immobilized) fluorescent Cy5 moleculesPictures: Tinnefeld LabFluorescence Techniques / GFPGreen Fluorescent Protein (GFP)Discovered in Jelly FishNobel Prize 2008Super-Resolution MicroscopySuper-Resolution Microscopy4 s movie of actin labeled Cy5 molecules under 100 µM AA –O21 ms integration timeReal-time movieAnalyzing frame by framePictures: Tinnefeld LabSuper-Resolution MicroscopyJ. Vogelsang, T. Cordes, C. Forthmann, C. Steinhauer, and P. Tinnefeld in PNAS 2009, 106, 8107-8112Pictures: Sauer LabActin Fibers stained with ATTO647Fret / QuenchingForce SpectroscopyDNA Force Extension by Magnetic TweezersBustamante LabApplying force to single moleculesMolecular function of musclePictures: Gaub LabEstimation of entropic forces on a polymerPictures: Gaub Lab- ATP+ ATP (2mM)Pictures: Gaub LabForce Spectroscopy with Optical TweezersOptical Tweezers A. Ashkin et al., Opt. Lett. 11, 288 (1986)Mie-Regime: Particle >> λ : ray-opticsRayleigh-RegimeParticle diameter << lambdaConsider particle as electric dipoleTypical Trapping wavelength: 1064 nmInvestigation of KinesinLight Driven MicrofluidicsLab-on-a-ChipControlled Fluid Flow without channels?Full Fluid Control100 µmSetup FluorescenceMicroscopex-y-scanner5 µmIR Laser @ 1450 nmWhat is the driving mechanism?Moving warm spotSpotFinite Element Analysisα Expansion Coefficientβ Temp. Dep. of Viscosityf Spot Repetition Rateb Spot WidthΔT Spot TemperatureF. M. Weinert, J. A. Kraus, T. Franosch and D. Braun, Phys. Rev. Lett. 100,164501 (2008)Temperature ImagingDependencies2TTTv fv Expansion coefficient and viscosityvMore Efficient towards Nanofluidics2/1 dv F. M. Weinert and D. Braun, J. Appl. Phys. 104, 104701 (2008).Full Fluid ControlMicrofluidics in GelsPumping in IcePumping in IceF. M. Weinert, M. Wühr and D. Braun, Appl. Phys. Lett. 94, 113901 (2009)Thermophoresis)exp(0TSccT: Thermodiffusion Coefficient: Soret CoefficientTowards a Molecule TrapPaternosterTowards AccumulationThermogravitational Separation ColumnConcentration Problem at the Origin of LifeP. Baaske, F. M. Weinert, S. Duhr, K. H. Lemke, M. J. Russell and D. Braun PNAS 104, 9346 (2007)Problem for Applications: long equilibration times ~ hours/daysLinear Clusius TubeTemperature Gradient & Bidirectional FlowBiderectional FlowThermophoresis + Bidirectional Flow = AccumulationAccumulation of 5 base single stranded DNASimulation of 50 base ss DNAVacuum Cleaner for 40nm beads(real time)Vacuum Cleaner for ss 50 base DNA40nm bead trapPolystyrene Spheres D = 40 nm, ST = 0.04 1/KMicrofluidics in IceParabolic BackflowAsymmetric PumpzzParabolic
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