Osmium tetroxide is a cornerstone fixative for transmission electron microscopy (TEM) and must be absolutely pure! The SPI-Chem™ brand of osmium tetroxide is EM grade and is available either as pure 99.995% crystals or, for convenience, as aqueous solutions. Both forms of the product are sealed under dry nitrogen in easy-to use, pre-scored safe, snap open ampoules for a one-time application and use. Osmium metal in many ways is unique among the elements and is even ""heavier"" than iridium, making it the heaviest of all the elements of the Periodic Table.
The glass ampoules containing the osmium tetroxide crystals arrive ""clean"" and there are no labels stuck to the ampoules nor is there any ink printing on the glass ampoules which can be a source for unacceptable levels of contamination. Where inks are used, there even can sometimes be a mild reaction with the osmium tetroxide, resulting in a diminution of the final strength of the working solution not to mention potential sample contamination. Although it would always be prudent to carefully wipe the outside of the ampoule with a lint free wiper, wet with a good solvent such as acetone just to remove any remaining finger prints, lint, or other contamination, there certainly will be no need to do any rubbing or scrubbing to remove the adhesive remains of some paper label once it has been applied to the outside of the ampoule.We serve the electron microscopy market worldwide:
SPI Supplies specializes in supplying the electron microscope user with their requirements for chemicals and consumables. Our ampoules are prepared with this one application in mind. Our prices are lower than what are generally found from a general lab supply house only because of the very large volumes we supply.