A commonly used method to measure the amount of DNA in nucleic acid preparations is to use UV irradiation. However, if the DNA sample contains impurities, measuring UV irradiation is misleading. A quick way to estimate the amount of DNA in such samples is to analyze spot densities created by UV-induced fluorescence emitted by ethidium bromide. The amount of DNA is proportional to the amount of fluorescence. In many references, the spot density analysis is recommended for rough estimation of DNA concentration and is done by visual examination and comparison of the densities of each spot with the densities of DNA standards. Herein, we used a computer-integrated software to test the reliability of such a method, and showed that the analysis is highly reliable and simple.

A commonly used method to measure the amount of DNA in nucleic acid preparations is to use UV irradiation. However, if the DNA sample contains impurities, measuring UV irradiation is misleading. A quick way to estimate the amount of DNA in such samples is to analyze spot densities created by UV-induced fluorescence emitted by ethidium bromide. The amount of DNA is proportional to the amount of fluorescence. In many references, the spot density analysis is recommended for rough estimation of DNA concentration and is done by visual examination and comparison of the densities of each spot with the densities of DNA standards. Herein, we used a computer-integrated software to test the reliability of such a method, and showed that the analysis is highly reliable and simple.