Enhanced FIB-SEM

Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) is an advanced technique to make 3D images of biological cells in tissues with superior z-axis (vertical) resolution, generating easily interpretable data for reconstruction. FIB-SEM produces detailed images of cell features like protein complexes and membranes through an electron beam's sequential etching of a sample surface. Until the developments of Enhanced FIB-SEM by C. Shan Xu and Harald Hess, presented here, the image produced had been limited to a single cell or small volume of cells.

The inherent technical limitations on FIB-SEM were slow imaging speed and lack of long-term system stability, which improved the abilities of TEM, still limited the image volume. However, the Hess lab masterfully re-engineered the FIB-SEM instrument orientation, reliability, and self-correction components, developed instrument designs, and techniques to accelerate image acquisition, and achieving dramatically improved performance.

This development continues with the full resources and attention of the FIB-SEM Technology, led by C. Shan Xu.

The enhanced FIB-SEM methods allow a system to operate continuously for months and image volumes greater than 10⁶ µm³. At this range, connectomics studies and mapping neuronal processes is possible, and it avoids tedious human proofreading. 

The subject of an issued US Patent, enhanced FIB-SEM includes the following features: 

1. In-line automatic focus, stigmation, and aperture alignment optimization

2. Temperature and currents monitoring

3. Closed-loop control of FIB milling

4. Email notification for warnings and auto-pause of operation to avoid sample damage

5. Auto restart after a pause

6. Multiple magnifications at user-selected intervals

7. Real-time image alignment

In more detail in the publication, the high-impact developments described here have made a substantial change in FIB-SEM enabled research, as shown by the 145 citations times of the first publication. The patent rights and designs are available for a commercial license for manufacture and sale. 

Intellectual Property:
US Patent 10,600,615
European Patent Application EP3574518A2