Analyzing DNA

Quantification of DNA

Getting reliable measurements of DNA concentration is important for many applications in molecular biology. Spectrophotometry and fluorometry are commonly used to measure genomic and plasmid DNA concentrations. Spectrophotometry can measure microgram quantities of pure DNA samples (i.e., DNA not contaminated by proteins, phenol, agarose, or RNA). Fluorometry is more sensitive, allowing measurement of nanogram quantities of DNA, and furthermore, the use of Hoechst 33258 dye allows specific analysis of DNA.