The A260/A280 ratio of nexttec DNA preparations is lower than with DNA prepared by other methods. How pure is DNA purified using nexttec kits?
Some substances from the lysis buffer remain in the DNA eluate. They cause a higher UV absorption at 260 and 280 nm. This leads to an overestimation of DNA concentration (up to 10-fold) and to a low ratio A260/280. The latter usually indicates a low purity of DNA preparations. But not with nexttec preparations! DNA isolated by nexttec kits is suited for demanding PCR applications and other enzymatic reactions. The results are comparable to those obtained with DNA purified with silica-based kits. The simplest way to determine the DNA concentration in nexttec™ DNA preparations is the agarose gel method. Another possibility is to determine the concentration by the fluorescent dye PicoGreen™. This method is the most sensitive and accurate, but a costly kit and a fluorescence reader are necessary.