Scanning Electron Microscopy Facility: FAQ
Analysis | |
| WD | Wavelength dispersive spectroscopy: For specific trace elements that will be dificult to identify or quantify in a large sample. |
| EDX | Energy dispersive spectroscopy: Please include all known elements of interest in EDX and note that noble gasses, H, Li and Be are not possible to analyse using EDX or WD |
| EDX Mapping | Please see image 1. This is a map of the selected area, with color overlays to indicate the presence of the elements and location (possible interaction or combination with other elements) in the sample. |
| EDX spot analysis (Point and ID) | Please see image 2: point and ID using a Spot analysis is a specific spot in a selected area that is being targeted with the beam. Please see image 3: A smaller area in this selected area can also be analysed using Point and ID. |
| STEM | STEM is a combo between SEM and TEM. The same sample prep is necessary for STEM as is for TEM which can be simple with staining and mounting onto a TEM grid or be extensive with fixation, embedding, microtoming (sectioning) and staining followed by mounting onto a grid. |
| SEM | Sample can be imaged at various resoltuions and for vraious purposes. Please make sure that you select the correct SEM for your samples type. |
| SBF | Serial block face analysis involving megametal protocol and resin embedding. |
Sample Preparation | |
| Fixation | This is required for frail, breakable samples (usually biological, organic samples) where the fine features need to intact. Fixation requires GLA, buffer solution, dehydration series with ethanol, HMDS or CPD |
| CPD | Crytical point drying is sometimes required if the HMDS solvent is to harsh for the drying final step of the samples preparation. |
| Staining | There are various types of staining required depending on the type of features you are interested in for your samples analysis. Please make sure to send or read up on protocols. The standard staining referred to here is negative staining with urinyl acetate (UA) for STEM. |
| Embedding (Resin) | This is done to preserve sample features if it is very fragile or it also normally required for geological material. If you are interested in seeing your enitre samples in sections and construct a 3D model you can refer to blockface analysis. |
| Blockface analysis | A beautiful, useful way of getting a 3D model view of your sample as a whole in order to see intrinsic structures (most commonly used for biological samples eg neuron systems in mice, small animal lung structrures) |
| Ultra-microtome | Method used to cut specimen into ultra-thin slices. Specimen require resin embedding for effective sectioning. |
Coating | |
| Carbon | Carbon coating is used in EDX to coat samples that are focussing on identifying or characterising gold (Au). |
| Gold | We use gold coating for samples where Au is not of interest in EDX analysis so that carbon coating will not interfer with C in sample if this is part of the list of EDX elements. Note that there will be miniscule Cu contamination that takes place as part of Au coating. In case of imaging the type of coating can be selected to fit suit the samples type and does not have a large impact. |
Other | |
| Magnificaton (resolution) | The magnification can be instructed to keep consistency with previous work or if you have nano-scale information to acquire. You can also let us know if you are interested in a broader-overall view of sample etc. |
| Sample specifications | Samples always need to completely dry and stable in vaccuum. Please communicate any significant details about the samples eg: possible beam sensitivity, biohazard materials, specific areas of interest, non-standard reasons for analysis |
| Please see image 4: ?Samples need to be small enough to fit into the
chamber of the Electron microscope.?? |
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