A method for measuring microquantities of DNA

✍ Scribed by Giachè, Valentino ;Pirami, Laura ;Becciolini, Aido

• Publisher: John Wiley and Sons
• Year: 1994
• Weight: 320 KB
• Volume: 9
• Category: Article
• ISSN: 0884-3996
• DOI: 10.1002/bio.1170090318

✦ Synopsis

Quantitative analysis o f DNA content represents a critical step when only very small amounts of nucleic acids are available. The DNA content of a small RNA-free sample can be measured in a simple and precise way using a two-dimensional approach. DNA samples are spotted on the surface o f an agarose gel containing ethidium bromide (EtBr) and the ultraviolet-induced low-light fluorescence emitted by EtBr molecules intercalated into the DNA is evaluated. The high sensitivity and reproducibility of this quantitative method has been obtained using an advanced analysis system capable o f distinguishing low-light fluorescent patterns, as in the case of DNA stained with EtBr, from the background. Use of an internal standard is necessary because the intensity o f the signal is due t o the aperture of camera diaphragm and t o gel conditions. Using this two-dimensional analysis system it is possible to obtain rapid and precise quantitation o f as little as 2ng of DNA.