Negative staining of particulate samples for Transmission Electron Microscopy (TEM)
Samples in solution (i.e. nanoparticles, micelles, exosomes, etc.) are air dried onto Silicone Monoxide treated, Formvar coated grids and subsequently stained with NanoVan.® Samples are then ready for imaging under the TEM.
Standard processing of biological samples for study by Transmission Electron Microscopy
This includes fixation, dehydration, and embedding in Araldite or EMbed 812 resin. Samples are then sectioned to obtain representative fields of the tissue/cell/structure. If specific structures within a cell or tissue are rare, then serial sectioning and staining of thick sections (see fee schedule below) may be required. Once sections are obtained, they are stained using 2% Uranyl Acetate followed by Reynold’s Lead Citrate.
Digital image acquisition on the Transmission Electron Microscope
Our FEI Tecnai G2 Spirit is equipped with an AMT digital imaging system. This system is capable of taking linear, on-screen measurements.
Quantitative analysis using stereology
If quantitative data about a structure or sub-cellular component are required for a project (i.e. number, volume, volume density, surface area etc.) the methods of stereology must be employed to yield statistically relevant results. This process generally requires serial sectioning, thick sectioning, photo prints, and increased image analysis time.
Immunocytochemistry
Using secondary antibodies conjugated to nanogold particles and post-embedding labeling, proteins of interest can be localized with sub-cellular resolution via TEM. Special considerations must be made on a project by project basis.
Standard processing of biological samples for study by Scanning Electron Microscopy (SEM)
This includes fixation, dehydration, and critical point drying. Specimens are then mounted on aluminum stubs and sputter coated with a gold/palladium alloy. The SEM allows for visualization of 3D surface topography and all images are acquired digitally.
Elemental Analysis of samples prepared for Scanning Electron Microscopy
Our FEI Quanta 200 is equipped with a Bruker AXS EDS detector. This addition allows for the generation of elemental maps of a sample through the use of Energy Dispersive Spectroscopy (EDS). This instrument is geared towards materials applications since the amount of high atomic numbered elements in biological samples typically falls below detection limits. However, there are biological applications of this technology (see image gallery for examples)