Tecnai g2 t12

For electron microscopic examination, Epon embedding was performed as previously described [23 (link)]. In brief, the rats (n = 4 for each group) were transcardially perfused with 2% glutaraldehyde (Gla) and 2.5% PFA in 0.1 mol/l PBS. Brains were quickly removed and placed on ice. The corpus callosum was dissected and placed in 3% Gla in 0.1 M cacodylate buffer (pH 7.4) at 4 °C overnight and transferred to 1% osmium tetroxide in the same buffer for 1 h at room temperature. Tissue was transversely cut into 1-mm blocks that were fixed in osmium tetroxide at 4 °C overnight, dehydrated through ascending ethanol washes, and embedded in epoxy resin. To study the remyelinated axons of the corpus callosum, serial 1-μm semi-thin sections were cut and stained with 1% toluidine blue and examined by light microscopy. To analyze myelin sheaths in the corpus callosum, 60~70-nm-thick ultra-thin sections were stained with uranyl acetate and lead citrate prior to examination by tEM (FEI Tecnai G2 T12, USA), and the image was analyzed by TEM Imaging and Analysis. For morphometric analysis, the axonal diameter (d) as the shortest distance across the center of the axon was measured. The axonal diameter plus the total myelin sheath thickness on both sides was defined as the fiber diameter (D). The g-ratio was calculated using the d/D ratio.

For the morphological characterization of bacteria, the bacterial suspensions of the abovementioned treatment groups were fixed overnight with a 2.5% glutaraldehyde solution after the assessment of antibacterial properties. Then they were dehydrated by sequential treatments with 30, 50, 70, 80, 90, and 100% of ethanol successively for 10 min. After drying with a critical point dryer, all samples were sputter-coated with platinum for SEM observation. Scanning electron microscopic images were recorded using a Tecnai G2 T12 instrument from FEI Company (United States). TEM images were recorded using an FEI TECNAI G220 high-resolution transmission electron microscope operating at 200 kV.

For transmission electron microscopy (TEM) observation, small samples of heart tissue were fixed in 2.5% glutaraldehyde overnight and then incubated while protected from light in 1% osmium tetroxide for 2 hours. After washing in distilled water, the specimens were incubated in 2% uranyl acetate for 2 hours at room temperature and then dehydrated in graded ethanol concentrations. Finally, the samples were embedded in molds with fresh resin. Ultrathin sections were obtained with an EM UC7 (Leica, Germany), stained with lead citrate and examined with a Tecnai G2 T12 (FEI, USA).