OSA's Digital Library

Virtual Journal for Biomedical Optics

Virtual Journal for Biomedical Optics


  • Editor: Gregory W. Faris
  • Vol. 3, Iss. 6 — Jun. 17, 2008

Controlling Brownian motion of single protein molecules and single fluorophores in aqueous buffer

Adam E. Cohen and W. E. Moerner  »View Author Affiliations

Optics Express, Vol. 16, Issue 10, pp. 6941-6956 (2008)

View Full Text Article

Enhanced HTML    Acrobat PDF (1027 KB) Open Access

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



We present an Anti-Brownian Electrokinetic trap (ABEL trap) capable of trapping individual fluorescently labeled protein molecules in aqueous buffer. The ABEL trap operates by tracking the Brownian motion of a single fluorescent particle in solution, and applying a time-dependent electric field designed to induce an electrokinetic drift that cancels the Brownian motion. The trapping strength of the ABEL trap is limited by the latency of the feedback loop. In previous versions of the trap, this latency was set by the finite frame rate of the camera used for video-tracking. In the present system, the motion of the particle is tracked entirely in hardware (without a camera or image-processing software) using a rapidly rotating laser focus and lock-in detection. The feedback latency is set by the finite rate of arrival of photons. We demonstrate trapping of individual molecules of the protein GroEL in buffer, and we show confinement of single fluorophores of the dye Cy3 in water.

© 2008 Optical Society of America

OCIS Codes
(180.2520) Microscopy : Fluorescence microscopy
(180.5810) Microscopy : Scanning microscopy
(300.6280) Spectroscopy : Spectroscopy, fluorescence and luminescence

ToC Category:

Original Manuscript: January 3, 2008
Revised Manuscript: April 23, 2008
Manuscript Accepted: April 30, 2008
Published: May 1, 2008

Virtual Issues
Vol. 3, Iss. 6 Virtual Journal for Biomedical Optics

Adam E. Cohen and W. E. Moerner, "Controlling Brownian motion of single protein molecules and single fluorophores in aqueous buffer," Opt. Express 16, 6941-6956 (2008)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. R. S. Van Dyck, P. B. Schwinberg, and H. G. Dehmelt, "New high-precision comparison of electron and positron g factors," Phys. Rev. Lett. 59, 26-29 (1987). [CrossRef] [PubMed]
  2. M. B. Comisarow and A. G. Marshall, "Frequency-sweep Fourier transform ion cyclotron resonance spectroscopy," Chem. Phys. Lett. 26, 489-490 (1974). [CrossRef]
  3. J. Enderlein, "Tracking of fluorescent molecules diffusing within membranes," Appl. Phys. B 71, 773-777 (2000). [CrossRef]
  4. A. J. Berglund and H. Mabuchi, "Feedback controller design for tracking a single fluorescent molecule," Appl. Phys. B 78, 653-659 (2004). [CrossRef]
  5. A. J. Berglund and H. Mabuchi, "Tracking-FCS: Fluorescence correlation spectroscopy of individual particles," Opt. Express 13, 8069-8082 (2005). [CrossRef] [PubMed]
  6. A. J. Berglund and H. Mabuchi, "Performance bounds on single-particle tracking by fluorescence modulation," Appl. Phys. B 83, 127-133 (2006). [CrossRef]
  7. A. J. Berglund, K. McHale, and H. Mabuchi, "Fluctuations in closed-loop fluorescent particle tracking," Opt. Express 15, 7752-7773 (2007). [CrossRef] [PubMed]
  8. D. Montiel, H. Cang, and H. Yang, "Quantitative characterization of changes in dynamical behavior for singleparticle tracking studies," J. Phys. Chem. B (2006). [CrossRef] [PubMed]
  9. H. Cang, C. M. Wong, C. S. Xu, A. H. Rizvi, and H. Yang, "Confocal three dimensional tracking of a single nanoparticle with concurrent spectroscopic readouts," Appl. Phys. Lett. 88, 223,901 (2006). [CrossRef]
  10. C. S. Xu, H. Cang, D. Montiel, and H. Yang, "Rapid and quantitative sizing of nanoparticles using three-dimensional single-particle tracking," J. Phys. Chem. C 111, 32-35 (2007). [CrossRef]
  11. S. Chaudhary and B. Shapiro, "Arbitrary steering of multiple particles independently in an electro-osmotically driven microfluidic system," IEEE Transactions on Control Systems Technology 14, 669-680 (2005).
  12. M. Armani, S. Chaudhary, R. Probst, and B. Shapiro, "Using feedback control and micro-fluidics to steer individual particles," Journal of Microelectromechanical Systems(JMEMS) 15, 945-956 (2006).
  13. A. E. Cohen and W. E. Moerner, "Method for trapping and manipulating nanoscale objects in solution," Appl. Phys. Lett. 86, 093,109 (2005). [CrossRef]
  14. A. E. Cohen and W. E. Moerner, "Suppressing Brownian motion of individual biomolecules in solution," Proc. Natl. Acad. Sci. USA 103, 4362-4365 (2006). [CrossRef] [PubMed]
  15. A. E. Cohen and W. E. Moerner, "Internal mechanical response of a polymer in solution," Phys. Rev. Lett. 98, 116,001 (2007). [CrossRef]
  16. A. E. Cohen and W. E. Moerner, "Principal Components Analysis of shape fluctuations of single DNA molecules," Proc. Natl. Acad. Sci. USA 104, 12,622-12,627 (2007). [CrossRef]
  17. A. E. Cohen, "Control of nanoparticles with arbitrary two-dimensional force fields," Phys. Rev. Lett. 94, 118,102 (2005). [CrossRef]
  18. A. E. Cohen, "Trapping and manipulating single molecules in solution," Ph.D. thesis, Stanford University (2007). Https://www2.lsdiv.harvard.edu/labs/cohen/Publications/AEC Thesis2 OneSided.pdf.
  19. A. E. Cohen and W. E. Moerner, "An all-glass microfluidic cell for the ABEL trap: fabrication and modeling," Proc. SPIE 5930, 191-198 (2005).
  20. H. Y. Wang, R. S. Foote, S. C. Jacobson, J. H. Schneibel, and J. M. Ramsey, "Low temperature bonding for microfabrication of chemical analysis devices," Sens. Actuators B 45, 199-207 (1997). [CrossRef]
  21. Z. Ding, G. Lai, T. Sakakibara, and S. Shinohara, "Determination of the spring constant of an optical trap by external sinusoidal excitation and lock-in detection," J. Appl. Phys. 88, 737-741 (2000). [CrossRef]
  22. S. S. Sommer and J. E. Cohen, "The size distributions of proteins, mRNA, and nuclear RNA," J. Molec. Evol. 15, 37-57 (1980). [CrossRef] [PubMed]
  23. S. Ghaemmaghami,W. Huh, K. Bower, R.W. Howson, A. Belle, N. Dephoure, E. K. O�??Shea, and J. S. Weissman, "Global analysis of protein expression in yeast," Nature 425, 737-741 (2003). [CrossRef] [PubMed]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited