Squishy Physics

Next seminar: Wednesday May 16th in Pierce 209 at 5:30 PM:


Dynamics of knotted DNA and knots in DNA


Alex Klotz

Departmant of Chemical Engineering

Massachusetts Institute of Technology


Knots occur naturally in biological DNA, a phenomenon relevant for cellular genome organization as well as genetic sequencing technology. Knotted DNA molecules serve as a model experimental system for polymer entanglement, where fluorescent microscopy can be used to study polymer dynamics on the individual chain level. To study the dynamics of knots in DNA, we induce knotting in viral DNA using an electrohydrodynamic instability and stretch the molecules with a divergent electric field in a microfluidic channel, analogous to elongational flow. I will discuss some recent results from our experiments and simulations, including the effect of knots on the entropic elasticity of a stretched molecule, the motion of knots along elongated molecules, and the process by which knots untie as they reach the end of the molecule.


Squishy Physics & Pizza Seminar Series

When: Wednesday Evenings - Pizza served at 5:20 PM, talks start at 5:30pm till...

Where: Room 301, Pierce Hall, 29 Oxford St, on the Harvard Campus. Directions and parking instructions are here.

What: These talks are informal, with emphasis on new results and ideas, rather than polished presentations. The Squishy audience members typically include soft matter scientists, physicists, engineers, chemists, and biologists.  The goal is to stimulate discussion with the audience.  Talks are typically about 45 minutes long, with lots of questions along the way.

Pizza: Only the finest! 

How to join the weekly Squishy Physics mailing list: please visit the Signup Page.

Directions: Where: Squishy Physics talks are held in Pierce Hall room 301, 29 Oxford Street, Cambridge, MA. See Harvard Campus map here.

Parking: Metered parking is available on Oxford Street.  Speakers, please contact Matthew Zahnzinger to obtain a parking permit.  

Squishy Physics is sponsored by the Cabot Corporation, Dean Cherry Murray and the Weitz Research Group.

If you have comments or suggestions or would like to give a talk, please contact Joerg Werner or Raoul Rosenthal.

Here is the upcoming schedule