You can't do it because DNA will interfere your protein CD spectra.

Cydi from EZBiolab

Hello,

in our lab we use CD of protein - DNA interactions. Circular dichroism signal of proteins is mainly located bellow 230 nm, so you can clearly observe the changes in DNA signal in 240 - 300 nm range.

Article Circular Dichroism for the Analysis of Protein-DNA Interactions

Hope this help

Thanks Cydi! I see what you meant. In my case, I only try to distinguish between naked DNA and protein bound DNA. Do you have any suggestion for which method I could use? Much appreciated!

And thanks for the information Martin. That's what I'm hoping for as well. Finger crossed. I'll do the CD measurement next week. Let's see