1. R. F. Bonner is in the Laboratory of Integrative and Medical Biophysics, National Institute of Child Health and Human Development, Bethesda, MD.
2. M. Emmert-Buck, K. Cole, R. Chuaqui, and L. Liotta are in the Laboratory of Pathology, National Cancer Institute, Frederick, MD.
3. T. Pohida is in the Computational Bioscience and Engineering Laboratory, NIH, Bethesda, MD 20852
4. S. Goldstein is in the Biomedical Engineering Program, NIH, Bethesda, MD 20852.