L-12 Advanced Replica techniques for TEM and high-resolution SEM

Life Sciences

"Quck-freeze/deep-etch" EM (DEEM) continues to occupy an useful 'niche' in the armamentarium of EM-preparative techniques, despite its relatively ancient origin over 60 years ago with the advent of the first high-resolution technique for the EM of molecules ('shadow-casting' by vacuum-evaporation of platinum by Williams and Wyckoff) and the amalgamation of 'shadow-casting' over 30 years ago with the then-new techniques of freeze-fracture and freeze-etching by Bullivant, Steere, Moor, and Branton. Particularly when combined with the slam-freezing technique of VanHarreveld and Heuser, DEEM still represents the only way that the surface-architecture of cells, organelles, and macromolecular complexes can be imaged in the EM without chemical fixation, and the only way that fast biological processes can be captured in real time. This session will aim to bring together current practitioners of this EM-approach, to illustrate their latest work, and to introduce the DEEM technique to a broader range of microscopists not already familiar with it. Reports are encouraged from biologists in all fields, from basic molecular and cell biology to microbiology, plant science, and especially from material-scientists interested in imaging the effects of applying "smart" nanomaterials onto living cells. The goal will be to illustrate how DEEM remains the only technique capable of integrating these diverse subjects, particularly because it avoids the curious 'explosion' of biological samples that inevitably occurs when high-pressure frozen biological samples are warmed in vacuo beyond -130ºC (the transition-temperature for glass-to-crystalline ice), as must be done to create 'deep-etch" platinum replicas.

Finally, reports will be especially encouraged and highlighted from practitioners of DEEM replica-immunolabelling, still the only way to simultaneously localize membrane proteins and lipids in the EM.

Chairpersons: