I am performing a gel extraction to purify DNA after a double digest with EcoRI and BamHI. After the gel extraction I need to complete a ligation step before bacterial transformation. The problem I am having is that the DNA after the gel extraction have some kind of chemical contaminant that won't allow me to quantify the DNA using the Nanodrop spectrophotometer. I am getting very low 260/230 ratios.
Has anyone had some issues with this?
I am using the Qiagen Qiaquick Gel Extraction Kit.