Cryo-Electron Microscopy allows us to peer into the world of cells and molecules around us. Affinity Capture technology is an innovative platform for visualizing molecules in action. We are developing this approach to transform our vision of the molecular world using cryo-EM and liquid cell EM.

Many important cellular events are mediated by large, dynamic complexes, which are impractical for NMR studies or are too unstable for crystallization. Therefore, structural information on many macromolecular machines is still very limited. Cryo-EM is an ideal technique to visualize protein assemblies, such as ribosomes, at sub-nanometer resolution. Still, a major obstacle in the field is that many active cellular complexes are too labile or in too low abundance for conventional purification schemes.

To address this issue, we developed a specialized molecular toolkit to rapidly prepare functional protein complexes for 3D structure determination. The monolayer purification method and the functionalized Affinity Grid allow us to purify complexes from crude cell lysates directly onto an EM Grid. These novel techniques provide a powerful approach for gathering structural information of functional cellular machines. Using these tools, we can examine biological processes in a completely new way. We are now applying this technology to isolate rare stem cells from normal and cancerous tissues.  This requires affinity matrices that can be used in conjunction with microfluidic devices to capture and image cells under various growth conditions. The knowledge gained from this line of research will shed light on the early events of stem cell commitment and of cancer formation.