Tris-HCl buffer with MgCl2 turns brown?

I am preparing 10mM Tris-HCl buffer for DNA aptamer with 200 mM NaCl, 25mM KCl, 10mM MgCl2 and a pH of 8. Because of the presence of MgCl2, the buffer is turning brown. Is it normal for the color...

01 July 2018 6,673 3 View