Does the conformation of both native and denatured DNA show any difference? I'm looking for double-stranded DNA which is in helix form in solution. Recently, i'd bought a calf-thymus DNA from Invitrogen. In the product description, it's said that "...the DNA is prepared from highly pure, phenol-chloroform extracted DNA, and DNAse-free, RNase-free, distilled, deionized water. Once dissolved, the DNA solution is sheared to an average size of <2000bp and the concentration is adjusted to 10mg/ml..." Does the shearing process destroy the helixity of the DNA?
Upon diluting the DNA, some undissolved material was observed (the solution was not clear due to this little suspension).. Does this a sign of DNA degradation? If i remove the undissolved material via centrifugation, do you think the DNA still ok for use? (According to one of my friend, the DNA solution should be clear in the concentration that i prepared. The solution was in 4e(-4) M in Tris / DMSO (9:1) solution. Tris buffer contains 5mM Tris, 50mM NaCl in pH 7.2)
Any idea to help?? Thanks..