1. Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
2. Innovative Genomics Institute, University of California, Berkeley, CA 94720
3. HHMI, University of California, Berkeley, CA 94720
4. Department of Chemistry, University of California, Berkeley, CA 94720
5. Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720