Associated Anisotropy Decays of Ethidium Bromide Interacting with DNA.

ABSTRACT: Ethidium Bromide (EB) is a commonly used dye in a deoxyribonucleic acid (DNA) study. Upon an intercalation, this dye significantly increases its brightness and fluorescence lifetime. In this report we have studied the time-resolved fluorescence properties of EB existing simultaneously in free and DNA-bound forms in the solution. Fluorescence intensity decays were fitted globally to a double exponential model with lifetimes corresponding to free (1.6ns) and bound (22ns) forms, and molar fractions were determined for all used solutions. Anisotropy decays displayed characteristic time dependence with an initial rapid decline followed by recovery and slow decay. The short-lived fraction associated with free EB molecules decreases faster than long-lived fraction associated with EB bound to DNA.

SUBMITTER: Chib R 

PROVIDER: S-EPMC4669070 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature