Digital optical and scanning probe microscopy for biocells inspection and manipulation

Abstract

Nanobiotechnology and scanning probe microscopy (SPM) are new fields that are of interest to modern medical science. Nowadays atomic force microscopy (AFM) is widely used in medical-biological researches from the all variety of SPM. Without special methods of preparation AFM gives an opportunity to investigate the morphology of the surface of different biological objects with nanoresolution. Also this method allows to analyze the physical and mechanical properties at micro- and nanoscale. Our experimental complex with the functions of scanning probe and optical microscopy is intended for different materials investigation including biological cells. A special optical system makes it possible to visualize the objects position of the probe in the microscale. AFM is used for visualization and identification of the local adhesion and viscoelastic properties of biological cells. Dynamic laser speckle (DLS) is used for real-time monitoring of cells motility in living tissues. Another opportunity of this complex is some manipulation with the cell by means of the applied load variation. This technique greatly enhances the possibilities and opens a new field of experiments in cell biology. The purpose of this work is to show the possibility of AFM and DLS for studies of biological cells, namely measurement of the general cells motility in living tissues, the elastic modulus of the single cell membrane, as well as to identify the forces causing damage of the membrane.