optical tweezers at the national institute of standards and technology and davidson college research...
TRANSCRIPT
Optical Tweezers
at
The National Institute of Standards and Technology and
Davidson College
Research performed by:
Rachel Patton McCord
Background: Optical Tweezers Physics • Balancing Forces:
• Scattering Force- “Radiation Pressure”• Gradient Force- Restoring force analogy to spring
Figure from: Svoboda and Block, 1994.
Physics, cont.• Tight focus = largest gradient force
• obtained with microscope objective
Images from: http://www.olympusmicro.com/primer/java/nuaperture/index.html
Basic Components
Objective LensL2 L3L1
f1 + f2 f3 16 cm
Image created from Physlet at http://webphysics.davidson.edu/Course_Material/Py230L/optics/lenses.htm Physlet by Dr. Wolfgang Christian and Mike Lee
Laser
NIST Alignment
• Gained experience with alignment by working on a two-laser trap setup.
Results
Single Trap
Both Traps Together
NIST Optical Tweezers Applications
• Liposomes• Stretching/Nanotubes• Microreaction Vesicles
• Single Mitochondria Isolation and Sorting• Available for PCR and genetic analysis
• Antigen/Antibody Binding• Quantum Dots in Polymersomes• Fluorescence Resonance Energy Transfer and
single molecule imaging
Davidson Setup
Results• Trapping microspheres in 3D
• 10 mW minimum power from laser (about 2 mW at the slide)
• Trapping single celled chlamydomonas
Image from: http://www.ucmp.berkeley.edu/greenalgae/chlorophyceae.html
Future Plans
• Force calibration• Measuring the swimming force of
chlamydomonas• Flagellar mutantsFurther in the future:• Physics Applications
• Stretching- elasticity, determining shear moduli
• Biology Applications• More chlamy- phototaxis• Virus adhesion
Acknowledgments• Dr. Kris Helmerson, Jeff Wells, Lara Crigger, Rani Kishore, Joe
Reiner at NIST
• Dr. John Yukich and Dr. Karen Bernd