Formvar carbon support film

Structural modification of hybrid poplar cell wall by pretreatment was studied using transmission electron microscope (TEM) combined with energy-dispersive X-ray spectroscopy (EDS) and electron energy-loss spectroscopy (EELS). The conditions used for pretreatment were identical to those used to prepare SEC samples. Cell wall samples of untreated hybrid poplar and hybrid poplar treated with AHP and Cu-catalyzed AHP for 24 h were air dried and fixed in 0.1 M pH 7.0 phosphate buffer [68 ] containing 2.5 % (w/w) glutaraldehyde and 2.5 % (w/w) paraformaldehyde. The fixed cell wall samples were embedded in Spurr epoxy resin (Poly/Bed 812, Polysciences) and sectioned to 100 nm thickness using a PowerTome XL ultramicrotome (Boeckeler Instruments, Tucson, AZ, USA). Thin sections were placed on 150 mesh gold grids with Formvar/carbon support film (Electron Microscopy Sciences, PA, USA) and stained in 1 % aqueous solution of KMnO₄ for 60 s. Samples were then rinsed with deionized water to remove excess stain. Bright field TEM micrographs and EELS spectra were acquired under a JEOL 2200FS 200 kV field emission TEM (Peabody, MA, USA) fitted with a Gatan (Warrendale, PA, USA) digital multi-scan camera. EDS spectra were acquired using an Oxford INCA system (Oxford Instruments, Abington, UK) coupled with the TEM.

Morphological and structural characterization of uncoated and chitosan-coated liposomal vesicles was done using transmission electron microscopy (TEM) employing an EM 208 (Philips) system equipped with a camera (Quemesa, Olympus Soft Imaging Solutions). For this analysis, samples were diluted 1 : 1 with distilled water, then deposited on a Formvar/carbon support film on a specimen grid (Electron Microscopy Sciences). After air-drying for 5 min, the sample was negatively stained with 1% (w/v) of uranyl acetate solution for 10 min.