Protocols | AFM
AFM (Atomic Force Microscopy)
This method describes general AFM (Atomic Force Microscopy) sample preparation and imaging. Specific parameters may vary depending on the protein sample being imaged and its buffer composition.
-
- Protein samples at 1-5 mg/mL are diluted 10-1 to 10-2 in F.S. dH2O and 20 uL is dropped onto Freshly cleaved mica (12mm, V1; VWR Cat 103302-494). The sample is incubated for 10-20 minutes at room temperature.
- Some samples do not readily stick to mica; in this case, the freshly-cleaved mica is pre-treated with 0.1% Poly-L-Lysine, washed with F.S. dH2O, and dried prior to sample addition.
- To wash away salts, 100 uL of F.S. dH2O is added to the surface and siphoned away using a fresh kimwipe. This is repeated a total of 2-5 times.
- The washed sample on mica is dried at room temp under a vacuum using a Vacufuge for 5-10 minutes until all liquid has evaporated.
- Samples are then imaged on a Nanosurf Core AFM using an ACSTA tip in tapping mode with a 500mV free vibration amplitude at a Z-controller setpoint of 55%.
- Protein samples at 1-5 mg/mL are diluted 10-1 to 10-2 in F.S. dH2O and 20 uL is dropped onto Freshly cleaved mica (12mm, V1; VWR Cat 103302-494). The sample is incubated for 10-20 minutes at room temperature.