1. Center for Bio/Molecular Science and Engineering, Naval Research Laboratory 4555 Overlook Ave SW Washington DC 20375 USA
2. Optical Sciences Division, Code 5600, U.S. Naval Research Laboratory 4555 Overlook Ave SW Washington DC 20375 USA
3. Oak Ridge Institute for Science and Education/US Army DEVCOM Chemical Biological Center, Biochemistry Branch, Aberdeen Proving Grounds Edgewood MD USA