Quantitative microscopy calibration techniques

Atomic force microscopy [6, 7] is one of the most suitable methods for research carbon nanotubes. AFM allows to receive not only a relief of the studied sample, but also distribution of mechanical characteristics, electric, magnetic and other properties on its surface. With the help of AFM, controllable manipulation of individual CNTs and CNTs bundles became possible. In this paper we report our approach to manipulating SWCNTs bundles with lateral force microscopy. LFM gives possibility to study lateral forces that probe acts upon bundles. In spite of good visualization of LFM, its lack is absence of reliable techniques of quantitative interpretation of results. The new way of calibration developed ourselves has allowed to pass from qualitative estimations to quantitative investigations [8], The given calibration technique is much more exact, than others known till now [9, 10], and does not assume simplification. With the help of new technique we may study adhesion of bundles to substrate and adhesion of CNTs in bundle qualitatively in real time more easy way. This result will provide new possibilities for nanotube application. 

It is also possible to record pH or [Ca ] directly using the appropriate indicators and quantitative confocal microscopy in a similar manner to that used to measure plasma and mitochondrial membrane potential directly (see Section 3.2.1). The great advantage of the direct technique is that it removes the requirement for the destructive titration/calibration procedures used by the other methods. This opens up the possibility of following dynamic changes in pH and cell calcium directly. 

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