I am using a purified recombinant protein to study the DNA binding.
I found out some "super bands" which migrate on top of the gel (closer to the loading well) at higher protein concentration (above apparent Kd). These bands are on top of the pr
-DNA complex band and not at the same position but keep closer to the loading wells.
DNA is P32 labeled 66bp long dsDNA 5'-overhang.
Protein concentration is kept in the range of [0, 500nM]. If the apparent Kd is about 150nM, the super band showed up at around 200 nM and the original Pr
-DNA band would disappear.
I suspect them as pr
-DNA aggregates. But I am not sure. Could anybody give me a hint? I'd like to upload the image, but don't know how.
Thanks a million!