I've seen some indications that cacodylate buffers can cause problems for SAD/MAD experiments. My initial impression was that this was just from the cacodylate leading to fluorescence spectra that shifts the apparent peak to lower energy. We've
solved a number of SAD structures (Br) in crystals grown in cacodylate buffer, but only recently have we run into a case that appears to have decent anomalous signal, but has proved difficult to find a reasonable solution. Is there some other effect that cacodylate
might be having, or is this likely just the case of poor energy choice and/or poorly ordered scatterers?
