Over the past 8 years, CBST has supported a collaboration led by UCSF and involving researchers from LLNL and UCD, to develop a new super-resolution optical imaging technique called structured-illumination microscopy (SIM). SIM represents a new generation of advanced fluorescence microscopy techniques capable of breaking the optical diffraction limit of 200-250 nm resolution, and the only one that uses widefield 3D imaging.  CBST received a Major Research Instrumentation grant from NSF to engage the only U.S. high-end microscope manufacturer, Applied Precision, Inc., A GE Healthcare Company, in developing the first commercial structured-illumination microscope.  While this instrument has already become a commercial success and has been well received by the biomedical research community, it is currently too slow to obtain super-resolution live cell images.  The development of a fast video-rate 3D SIM system with CBST's participation will for the first time make available to the biological community the new high-speed imaging of SIM systems.