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Nano-engineered, Ultra Stable, Live Cell Vaccines Against Tuberculosis
Scannin Electron Microscopy and Fluorescent images
![Scannin Electron Microscopy and Fluorescent images](/system/content_item_assets/images/1168/large/0549500_2011_Johnson_Fig._1.jpg)
Fig. 1. Individual, dry particles are visualized with scanning electron microscopy (a) and compared to fluorescence images (b,c) of a similar particle, which show the complete encapsulation of E. coli cells expressing a red fluorescent protein. Transmission electron microscopy demonstrates high nanoscopic ordering in the region directly adjacent to an encapsulated cell (d). Fluorescence Recovery After Photobleaching measures the fluid micro-architecture within the dry particle (e-h). An area of known diameter is bleached completely (yellow arrow, f) & the time to recovery of fluorescent molecules is determined. Thermal stability of E. coli encapsulating bio-nano composites was characterized using a viability assay that releases a luminescent molecule in the presence of ATP. This assay was applied to samples aged under refrigerated & accelerated conditions over a three month period (i).
Credits: Patrick Johnson, University of New Mexico