Sample preparation will vary depending on the sample, imaging mode, and size of desired images.
You will likely need to do a literature search to find the preparation best for your sample. Smaller images or more complex imaging modes will demand more stringent sample preparation.
General Preparation
Mandatory
- The sample must be less than 7 mm in height.
- The sample must be securely affixed to a glass slide.
Recommended
- Samples should be relatively flat, and have few to no gashes, ridges, or other defects over 1 um in size.
- Samples should have no adhesive substances on them.
- Samples should be clean.
Liquid Imaging
The full sample preparation will be dependent on the sample.
- Substrates: Common substrates for droplet imaging are mica, HOPG (highly oriented pyrolytic graphite), silicon or gold.
- Support:
- The substrate must be affixed to a glass slide for imaging.
- Epoxy or super glue are recommended.
- Carbon tape should also work.
- To create a droplet there must be a hydrophobic region surrounding the substrate.
- PAP pens are the most convenient.
- Teflon (threading) tape
- Parafilm
- PTFE (polytetrafluoroethylene, or Teflon) printed slides
- High vacuum grease
- Set up samples in a manner that liquid will stay locked into one area on the substrate
(glass slide).
- Use parafilm, carbon tape, or other hydrophobic material to isolate a central zone on the slide where liquid/buffer and sample will reside.
- Alternatively, use the petri dish setup and fully immerse samples within it with some additional setup.
- The substrate must be affixed to a glass slide for imaging.
- Sample: The sample will need to be affixed to the substrate.
- Solution: It is best to have the solution at room temperature.
Conductive Imaging
- The sample being used must be the proper dimensions for CAFM, Conductive Atomic Force Microscopy. It has to be 1-5 cm in diameter and less than 1 mm thick for optimal results.
- Conductive AFM must be done either on dry samples or with non-electrolytic liquids.