Digital Optical and Scanning Probe Microscopy for Inspection and Manipulation of Biocells - Bioanalysis Advanced Materials Methods and Devices - page 101

needs to be extracted. Although the data obtained is seen to be proportional to the
velocity of the scatterers, the effect of multiple scattering causes difficulties in
obtaining the absolute value of the blood velocity. Therefore, the monitoring
reported here is qualitative and the blood flow maps are presented in arbitrary units.

7.8 Conclusions

This investigation reveals the twin potential of AFM for making measurements of
the mechanical properties of cells and in performing certain actions on them,
combined with DLS for evaluation of erythrocyte motility. There are two main
methods for the manipulation of living cells using AFM: by elasticity measurement
and direct application of force. We have determined the forces under which the cell
membrane may be cut. Further, we have demonstrated the potential of obtaining the
quantitative characteristics of cellular mechanical properties for cases of patho-
physiological disorders of cells such as diabetes mellitus type II and cancer. These
have enabled us to examine how experimental results of force measurements may
be used to deduce a guiding principle for the magnitude of forces required for cell
manipulation: the objective is to aid cellular level surgery. Quantitative monitoring
of erythrocytes motions in living tissues with the use of DLS methods has also been
demonstrated. The proposed software makes it possible to recover up to 25,000
motion vectors in a two-dimensional flow region of size 20 30 mm, providing

real-time spatial resolution of about 100 m m.

Acknowledgments The authors wish to thank Dr. Serguei Rubnikovich (Belarus Medical State
University, Minsk), Dr. Nikolai Bazylev, and Ms. Olga Meleeva (Heat and Mass Transfer
Institute) for the help in images treatment and manuscript preparation as well as the National
Academy of Sciences and Foundation for Basic Research of Belarus for partial financial support of
the work with grants and projects “Energy Efficiency EE 1.6.1,” T11MC-023, T10-029.

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