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> I had a simple question about DNA binding protein. Is there an > easy way to detect if your heterologously expressed protein is bound to > DNA post purification. Yes. UV absorbance. DNA absorbs UV strongly, proteins do not. DNA absorbs 260 more thn 280, the opposite is true for proteins. In fact, it's always a good idea to check 260/280 ratio because quite frequently even non-DNA binding proteins purified by a single tag affinity chromatography contain enough DNA to skew estimation of protein concentration from 280 nm absorbance by several fold (9X in one case of my personal experience). >Also is there an easy way to strip the protein of DNA without any damage >done to the protein in doing so. No generic solution. Greatly depends on the protein and its properties. Dima