High-Resolution Field Emission Scanning Electron Microscopy (FESEM) Imaging of Cellulose Microfibril Organization in Plant Primary Cell Walls. (24th August 2017)

• Record Type: Journal Article
• Authors: Zheng, Yunzhen; Cosgrove, Daniel J.; Ning, Gang
• Is Part Of: Microscopy and microanalysis. Volume 23:Number 5(2017)
• Page Start: 1048
• Page End: 1054
• Publication Date: 2017-08-24
• Subjects: high-resolution scanning electron microscopy, -- field emission scanning electron microscopy, -- epidermal cell walls, -- cellulose microfibrils, -- iridium sputter coating; Microscopy -- Periodicals; Microchemistry -- Periodicals; 502.82
• DOI: 10.1017/S143192761701251X
• Languages: English
• ISSNs: 1431-9276

Abstract

Abstract: We have used field emission scanning electron microscopy (FESEM) to study the high-resolution organization of cellulose microfibrils in onion epidermal cell walls. We frequently found that conventional "rule of thumb" conditions for imaging of biological samples did not yield high-resolution images of cellulose organization and often resulted in artifacts or distortions of cell wall structure. Here we detail our method of one-step fixation and dehydration with 100% ethanol, followed by critical point drying, ultrathin iridium (Ir) sputter coating (3 s), and FESEM imaging at a moderate accelerating voltage (10 kV) with an In-lens detector. We compare results obtained with our improved protocol with images obtained with samples processed by conventional aldehyde fixation, graded dehydration, sputter coating with Au, Au/Pd, or carbon, and low-voltage FESEM imaging. The results demonstrated that our protocol is simpler, causes little artifact, and is more suitable for high-resolution imaging of cell wall cellulose microfibrils whereas such imaging is very challenging by conventional methods.