Taekjip Ha

Adjunct Professor


Taekjip  Ha

Primary Research Area

  • Biological Physics


Professor Taekjip Ha received his Ph.D. in Physics in 1996, from the University of California, Berkeley. Prior to joining the Physics faculty at the University of Illinois in August 2000, he was a postdoctoral fellow at Lawrence Berkeley National Laboratory (1997) and a postdoctoral research associate in Steven Chu's laboratory in the Department of Physics at Stanford University (1998-2000). He was named 2001 Searle scholar. In 2005, Dr. Ha was named an investigator of the Howard Hughes Medical Institute. In 2008, Dr. Ha was selected by the National Science Foundation to receive a grant to establish and co-direct the Center for the Physics of Living Cells at the University of Illinois.

Professor Ha has achieved many "firsts" in experimental biological physics--the first dectection of dipole-dipole interaction (fluorescence resonance energy transfer, or FRET) between two single molecules; the first observation of "quantum jumps" of single molecules at room temperature; the first detection of the rotation of single molecules; and the first detection of enzyme conformational changes via single-molecule FRET. His most recent work, using single-molecule measurements to understand protein-DNA interactions and enzyme dynamics, has led him to develop novel optical techniques, fluid-handling systems, and surface preparations.

Research Statement

My interest is in using physical concepts and experimental techniques to study fundamental questions in molecular biology. The biological systems under study include helicases that unzip DNA, DNA recombination intermediate called Holliday junction and its associated enzymes, folding and catalysis of hairpin and VS ribozymes, DNA replication machinery, and chromatin remodeling complexes. Our main experimental tool is single-molecule fluorescence spectroscopy and microscopy, supported by nano-mechanical tools such as magnetic and optical tweezers.


  • University Scholar, University of Illinos (2009-2010)
  • National Science Foundation Award, Center for the Physics of Living Cells (2008)
  • Michael and Kate B?ny Award for Young Investigators, Biophysical Society (2007)
  • Fellow, American Physical Society (2005)
  • Howard Hughes Medical Institute Investigator (2005)
  • Alfred P. Sloan Fellow (2003)
  • Xerox Faculty Research Award, UIUC (2003)
  • Beckman Fellow at Center for Advanced Studies, UIUC (2003)
  • Cottrell Scholar, Research Corporation (2003)
  • Fluorescence Young Investigator Award, Biophysical Society (2002)
  • NSF CAREER Award (2002)

Semesters Ranked Excellent Teacher by Students

Spring 2013PHYS 101

Selected Articles in Journals

  • S. Myong, I. Rasnik, C. Joo, T. M. Lohman, and T. Ha. Repetitive shuttling of a motor protein on DNA. Nature 437, 1321-1325 (2005).
  • I. Rasnik, S. A. McKinney and T. Ha, Non-blinking and long-lasting single molecule fluorescence imaging. Nature Methods 3, 891-893 (2006).
  • S. Myong, M. M. Bruno, A. M. Pyle and T. Ha, Spring-loaded mechanism of DNA unwinding by Hepatitis C Virus NS3 helicase, Science 317, 513-516 (2007).
  • S. Hohng, R. Zhou, M. K. Nahas, J. Yu, K. Schulten, D. M. J. Lilley and T. Ha, Fluorescence-force spectroscopy maps two-dimensional reaction landscape of the Holliday junction, Science 318, 279-283 (2007).
  • S. Myong, S. Cui, P. V. Cornish, A. Kirchhofer, M. U. Gack, J. U. Jung, K. P. Hopfner and T. Ha, Cytosolic viral sensor RIG-I is a 5'-triphosphate-dependent translocase on double-stranded RNA, Science 323(5917):1070-1074 (2009).
  • R. Roy, A. G. Kozlov, T. M. Lohman and T. Ha, SSB protein diffusion on single-stranded DNA stimulates RecA filament formation, Nature 461(7267), 1092-1097 (2009).
  • M. Pandey, M., S. Syed, I. Donmez, G. Patel, T. Ha and S. S. Patel, Coordinating DNA replication by means of priming loop and differential synthesis rate, Nature 462, 940-943 (2009).
  • C. Grashoff, B. D. Hoffman, M. D. Brenner, R. Zhou, M. Parsons, M. T. Yang, M. A. McLean, S. G. Sligar, C. S. Chen, T. Ha and M. A. Schwartz, "Measuring Mechanical Tension Across Vinculin Reveals Regulation of Focal Adhesion Dynamics", Nature 466, 263-266 (2010).
  • A. Jain, R. Liu, B. Ramani, E. Arauz, Y. Ishitsuka, K. Ragunathan, J. Park, J. Chen, Y. K. Xiang and T. Ha, "Probing cellular protein complexes using single-molecule pull-down", Nature 473, 484-488 (2011).
  • R. Zhou, A. G. Kozlov, R. Roy, J. Zhang, S. Korolev, T. M. Lohman and T. Ha, "SSB functions as a sliding platform that migrates on DNA via reptation", Cell 146, 222-232 (2011).
  • I. Cisse, H. Kim and T. Ha, "A rule of seven in Watson-Crick base pairing of mismatched sequences," Nature Structural & Molecular Biology 19, 623-627 (2012).
  • G. Lee, M. Bratkowski, F. Ding, A. Ke and T. Ha, "Elastic coupling between RNA degradation and unwinding by an exoribonuclease," Science, 336, 1726-1729 (2012).
  • R. Vafabakhsh and T. Ha, "Extreme bendability of DNA less than 100 base pairs long revealed by single molecule cyclization," Science, 337, 1097-1101 (2012).

Books Edited or Co-Edited (Original Editions)

  • Selvin, P.R. and T. Ha, editors, Single Molecule Techniques: A Laboratory Manual, Cold Spring Harbor Laboratory Press, 507 pp., ISBN 978-087969775-4 (2008).

Related news

  • Accolades
  • Biological Physics
  • Biophysics

The National Academy of Sciences has elected to membership Taekjip Ha, the Edward William and Jane Marr Gutgsell Professor of Physics at the University of Illinois at Urbana-Champaign.


Head of Department and Professor Dale Van Harlingen said, “Taekjip is a deserving and welcome addition to the academy membership. His innovative work has stretched the boundaries of biological physics, and he is a true visionary in his field. Through his many fruitful collaborations, Taekjip has substantially contributed to the agenda of several strategic campus research initiatives. And he has done much to position Illinois as a world leader in biological physics."

  • Accolades
  • Biological Physics
  • Biophysics

Three University of Illinois professors have been elected to the American Academy of Arts and Sciences, one of the longest-standing honorary societies in the nation. Physics professor Taekjip Ha will join psychology professors J. Kathryn Bock and Gary S. Dell and other new members in an induction ceremony in October in Cambridge, Massachusetts.

Ha is the Edward William and Jane Marr Gutgsell Endowed Professor, a Howard Hughes Medical Institute Investigator, a professor in the Beckman Institute and the Cellular Decision Making in Cancer theme leader in the Carl R. Woese Institute for Genomic Biology at Illinois. He also is co-director of the National Science Foundation-funded Center for the Physics of Living Cells at the U. of I.

  • Research
  • Biological Physics
  • Biophysics

By combining two highly innovative experimental techniques, scientists at the University of Illinois at Urbana-Champaign have for the first time simultaneously observed the structure and the correlated function of specific proteins critical in the repair of DNA, providing definitive answers to some highly debated questions, and opening up new avenues of inquiry and exciting new possibilities for biological engineering.

Illinois biological physicists Taekjip Ha and Yann Chemla have combined two cutting-edge laboratory techniques that together directly get at the structure-function relationship in proteins. Ha is well recognized for his innovative single molecule fluorescence microscopy and spectroscopy techniques. Professor Yann Chemla is a top expert in optical trapping techniques. Their combined method—simultaneous fluorescence microscopy and optical trapping—yields far more definitive answers to questions relating structure to function than either technique could independently.


  • Research
  • Biological Physics
  • Biophysics

“We discovered this interesting physics of DNA that its sequence determines the flexibility and thus the stability of the DNA package inside the cell,” said Gutgsell Professor of Physics Taekjip Ha, who is a member of the Carl R. Woese Institute for Genomic Biology. “This is actually very elementary DNA physics. Many people thought we should have known this many decades ago, but there are still surprises in the physics of DNA.”