Department of Biomaterials: Faculty Corner
A new Zeiss GeminiSEM 300 Field Emission-Scanning Electron Microscope will be housed in the Department of Biomaterials under Dr. Bromage’s Histology and Correlative Microscopy Core (HCMC) facility at NYU College of Dentistry. Dr. Bromage received an NIH Shared Instrumentation Grant (S10OD026989) of $581,107 to acquire the new microscope which is replacing the aging Zeiss EVO 50 SEM. The HCMC is dedicated to the highest quality research on skeletal tissues and dental materials. The Core provides its users expertise in undercalcified tissue and synthetic specimen preparation as well as imaging support for NYU Dentistry bone, tooth, and oral health research programs. Replacement of the current EVO SEM with the Gemini VP FE-SEM will provide a major step forward, not only in the overall quality of images, but also in the possibility of visualizing details that were not visible with conventional SEM.
Pictured Zeiss demo lab GeminiSEM 300FE-SEM, detailed column design and VPSE detector.
The GeminiSEM 300 is a VP FE-SEM with accelerating voltages ranging from 0.2 kV to 30 kV, beam current ranging from 3 pA to 20 nA, and nominal resolution ranging from 0.8 nm at 15 kV to 1.4 nm at 1 kV, which provides good resolution even at the low voltages. The instrument has both an annular in-lens secondary electron (SE) and an annular in-lens energy selective “low loss” backscattered electron detector (BSE). These detectors may be operated at up to 150 Pa pressure in so-called "NanoVP" mode for topographic and material properties signals respectively.
At up to 500 Pa pressure, topographic as well as density-dependent compositional imaging is afforded respectively by a VP SE detector and a pneumatic retractable solid state angle-selective BSE detector. A standard Everhart-Thornley detector allows high vacuum SE imaging. The machine is expected to arrive this Fall 2019. For more information, please contact Dr. Bromage.
Dr. Timothy Bromage’s image of a mouse incisor tip enamel, showing deficiencies (linear voids) in enamel structure compared to controls, was featured on the April 2019 cover of Science Signaling. (Field width 100 µm.) The research article reveals that SOCE mediated by ORAI1 affects the metabolism, redox status, and function of enamel cells in teeth. SE/BSE image acquired using a Zeiss EVO-50 in Dr. Timothy Bromage's Histology and Correlative Microscopy Core, NYU Dentistry Department of Biomaterials.
Eckstein M, Vaeth M, Aulestia FJ, Costiniti V, Kassam SN, Bromage TG, Pedersen P, Issekutz T, Moursi AM, Feske S, Lacruz RS. Differential regulation of Ca2+ influx by ORAI channels mediates enamel mineralization. Science Signaling, 12: eaav4663.
Dr. Yu Zhang’s research was featured on the April 2019 cover of JDR. Scanning electron microscopy image showing the microstructure of the zirconia used in the study.
Ramos, N. C., Kaizer, M. R., Campos, T. M. B., Kim, J., Zhang, Y., & Melo, R. M. (2019). Silica-Based Infiltrations for Enhanced Zirconia-Resin Interface Toughness. Journal of Dental Research, 98(4), 423–429.