DNA conformational studies from electron microscopy. I. Excluded volume effect and structure dimensionality

Abstract
Plots of end‐to‐end distance (R0) vs contour length (S) measured from electron micrographs of double‐stranded DNA molecules reveal typical power laws (R0S3/5 and S3/4) and confirm the evident qualitative differences of structure observed when using various spreading techniques. We propose to relate these power laws to the structure dimensionality of DNA as a function of the conditions of spreading. To pursue this idea, our experimental results are compared with models of polymer conformation that incorporate the excluded volume effect.