In both cases the fluorescent particles are 2 microns in diameter. The left picture shows particles moving in pure water; the right picture shows particles moving in a concentrated solution of DNA, a viscoelastic solution in other words. The movies are 4 seconds of data, total; you can see a slight jump in the movie when it loops around.

With these sorts of images, we can do microrheology.

This page is was written by Eric Weeks. If you have questions or comments, email me: erweeks / emory.edu