On May 20, 2013, at 7:20 AM, A K <alek6...@gmail.com> wrote: > Dear all, > I have a crystallization-related question. I am going to co-crystallize > protein with RNA. I ordered a short (10 mer and 14 mer) RNA from Dharmacon > but did not choose the purification option while ordering them due to the > budget issues. How critical is to HPLC purify them before setting drops? > Aren't RNA synthesis protocols reliable enough nowadays for such short RNAs? > Thanks, > Alex
Dear Alex: The coupling steps are rather more inefficient than with DNA, so you may have some non-negligible N-1, N-2, .. contaminations, as well as potentially incompletely deprotected RNAs. If the RNA is involved in making lattice contacts, this might be problematic. However, crystallization is also a purification procedure, so you could always try it first and see if it works. In one case in our lab, having a contaminant like this present was absolutely essential for obtaining crystals. Gel purification is cheap and easy, and not too much of a burden if you can avoid getting skin cancer from the UV light needed for shadowing the RNA. A 20% acrylamide sequencing gel mix would give you the nucleotide resolution you might need. Good luck. Bill William G. Scott Professor Department of Chemistry and Biochemistry and The Center for the Molecular Biology of RNA 228 Sinsheimer Laboratories University of California at Santa Cruz Santa Cruz, California 95064 USA
