  We developed the models and algorithms to describe two main artefacts of AFM:
(i) broadening effect and (ii) decreased heights of profiles for individual
objects adsorbed on a hard substrate. It was shown how to measure elastic
properties of a single adsorbed microobject. From the viewpoint of contact
deformation theory we analysed mechanism of AFM visualisation of an atomic
(molecular) structure of a flat surface. We tested technique of immobilisation
on a substrate for free single-stranded RNA molecules in an extended state.
Using AFM we visualised stages of processes of RNA release from protein coat of
tobacco mosaic virus particles. The asymmetry of this process regarding two
ends of a macromolecule was confirmed. The dynamics of compaction for DNA T4
molecules was traced using AFM in real time regime. The partially compacted
macromolecules were clearly resolved. We detected that the partially compacted
structures consisted of toroidal parts formed by different macromolecular
strands. The real geometry of the compacted structures was reconstructed on the
basis of systematic AFM measurements. That allowed us to calculate the amount
of molecules combining each condensed DNA particle. We demonstrated clear
benefits of horizontal deposition method for formation of LB films. Using AFM
we achieved molecular resolution for some thin film coating and detected
lattice parameters with the precision determined by the errors within a few
percent. We demonstrated that the structure of the film is determined by the
concurrence of several factors: by the closest packing principle for
hydrocarbon tails, by the values of surface areas of polar heads at water
subphase as well as by the substrate influence.
