Typical AFM image of the DNA test sample (obtained in noncontact mode, humidity is 1-10%, Solver P47BIO, NT-MDT-SI.).
DNA01 is Plasmid pGem7zf+ (Promega) which is linearized with the SmaI endonuclease. A linear DNA molecules (3000 b. p.) are deposited onto freshly cleaved mica. Molecules are uniformly distributed on the surface with molecule density - 0,5-7 molec./um2 and typical DNA length 1009 nm. Recommended humidity for obtaining a good image is 3-5%.
- getting start in working on AFM with biological samples;
- using like a sample for preparing DNA samples by your own;
- estimation of cantilevers tip radius curvature (since the DNA size is equal two nanometres in free condition);
- test samples for Z-resolution of commercial SPMs.