1. Department of Cellular and Regenerative Biology, University of Wisconsin–Madison, Madison, WI 53706
2. Laboratory of Cell and Molecular Biology, University of Wisconsin–Madison, Madison, WI 53706
3. Laboratory of Optical and Computational Instrumentation, University of Wisconsin–Madison, Madison, WI 53706
4. Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213
5. Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104