Potassium permanganate is an excellent alternative to osmium tetroxide in freeze-substitution

High-pressure freezing followed by freeze-substitution is a valuable method for ultrastructural analyses of resin-embedded biological samples. The visualization of lipid membranes is one of the most critical aspects of any ultrastructural study and can be especially challenging in high-pressure frozen specimens. Historically, osmium tetroxide has been the preferred fixative and staining agent for lipid-containing structures in freeze-substitution solutions. However, osmium tetroxide is not only a rare and expensive material, but also volatile and toxic. Here, we introduce the use of a combination of potassium permanganate, uranyl acetate, and water in acetone as complementing reagents during the freeze-substitution process. This mix imparts an intense en bloc stain to cellular ultrastructure and membranes, which makes poststaining superfluous and is well suited for block-face imaging. Thus, potassium permanganate can effectively replace osmium tetroxide in the freeze-substitution solution without sacrificing the quality of ultrastructural preservation.

Hierarchical α-MnO2 Nanowires as an Efficient Anode Material for Rechargeable Lithium-Ion Batteries

In this work, a bulk quantity of α-MnO2 hierarchical nanowires synthesized by a facile redox reaction between potassium permanganate (KMnO4) and glycine under ambient conditions. The physicochemical characterization results reveal...

Potassium Permanganate Dye Removal from Synthetic Wastewater Using A Novel, Low-Cost Adsorbent, Modified from The Powder of Foeniculum Vulgare Seeds

Seeds powder of Foeniculum vulgare (FVES) was used to prepare a novel adsorbent, the new adsorbent was characterized and its ability to eliminate potassium permanganate (KMnO 4 ) was examined. The impact of KMnO 4 concentration, adsorbent dose, contact temperature, contact time, and solution pH on the adsorption performance was also investigated. The experimental data of this adsorption was analyzed by different kinetic and isotherm models. As Constants of thermodynamic ΔG°, ΔH°, and ΔS° have been also evaluated. Surface area, pore volume, and pore size of the FVESP adsorbent were determined as 0.6806 m 2 .g -1 , 0.00215 cm 3 .g -1 , and 522.063 Å, as pH ZPC of Ox- FVESP was stated to be 7.2. The R 2 values obtained from applying different isotherm and kinetic models (0.999 and 0.996) showed that the adsorption performance of KMnO 4 follows the Langmuir and Pseudo 2 nd order models. Furthermore, high adsorption capacities of 1111.11, 1250.00, and 1428.57 (mg/g) were achieved at three temperatures that were used in this study. Constants of thermodynamic ΔG°, ΔH°, and ΔS° values indicate chemical and spontaneous adsorption at the adsorbent surface.