Tuesday, May 17, 2011

Day 1 - Foreigners hit the books

With a summer theme of Bio-Physics, it would seem important for Fash and Benjamin (the Foreign factor of the lab), the young Nigerian and New Zealand aspiring physicist to brush up on the prefix (Bio). Currently, although we are well versed in physical ideas, such as electrostatic repulsion, Fash's and my biological knowledge doesn't extend further then a semester of bio 112; leaving us about as lost as we felt line dancing at the local rodeo last weekend (although Fash did suit his pink rodeo hat).

Today -- and most likely the remainder of the week -- will be dedicated to becoming acclimated with the biological and chemical content of the Andressen lab, and also getting a good grasp on prior work that has been conducted on the unusual properties of DNA.

From the literature we covered today (DNA-Inspired Electrostatics - W. Gilbert, Electrostatics of Strongly Charged Biological Polymers: Ion-Mediated Interactions and Self-Organization in Nucleic Acids and Proteins - G. Wong, L. Pollack) the interesting behavior of DNA came to the forefront of Fash and my bilingual discussions. Switching effortlessly between New Zealandish, English and American, we conversed about the theme of electrostatics. We agreed that one of the most striking aspects of DNA was its charge to length ratio. The long thin DNA coil contians one unit of negative fundamental charge every 0.17nm of length. Even more remarkable than this fact, are the experimental observations that despite the repulsive effects one might expect from such dense, like charge, the DNA attracts itself under a range of solution conditions. This was a recurring theme in the literature studied, with numerous theories including Poisson-Boltzmann Mean-Field Theory, presented in an attempt to explain this unintuitive phenomena.

Also applicable to the work we will be doing was the descriptions of how DNA acts in varying ionic solutions. When placed in "physiological conditions," (1MolL-1 NaCl) the DNA follows the shape of a coil, however, when placed in a highly dilute solution, the DNA forms into a torus (donut) shape with an average radius of 50nm. This resembles the experiments the foreign factor will most likely be looking into. However, instead of dealing with isolated DNA, we will be looking at how DNA, with nucleosomes still present within the structure, will act in varying solutions.

That seems like enough of an introduction, apologies for the accents, and until tomorrow, the Foreign half of team Andressen is out.

No comments:

Post a Comment