1. Federal Bureau of Investigation, Laboratory Division, Quantico, VA 22135, USA.
2. University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Department of Medicine, Newark, NJ 07103, USA.
3. Russell Research Center, U.S. Department of Agriculture, Athens, GA 30604, USA.
4. Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA.
5. Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
6. Department of Laboratory Medicine, Children's National Medical Center, Washington, DC 20010, USA.