Campione biologico standard con plasmide DNA pUC19 e un batteriofago filamentoso M13.

The sample contains a circular plasmid DNA pUC19 and a filamentous bacteriophage M13. pUC19 is one of the most widely used vector molecules and has a 2686 base pairs double stranded DNA. The expected contour length of the plasmid molecule is 800 nanometers. M13 is widely used in phage display technology as well as in nanotechnology. The expected contour length of the bacteriophage is ~900 nanometers. Structures are uniformly distributed on the surface with molecule density 4-6 molecules/µm2.

Example of AFM topography obtained on BS01 sample is shown below.

Probe Etalon HA_NC has been used for the measurements.

Scan sizes: 2 x 2 x 0.005µm Cross section A-A'

 

Applications:

    - getting start in working on AFM with biological samples;

    - using like an example for preparing DNA and bacteriophage samples by your own;

    - estimation of cantilevers tip radius (typical DNA size on the mica is 0.5-0.7 nm, bacteriophage size is 3-4nm);

    - test samples for Z-resolution of commercial SPMs.