VIDEOMICROPY OF LIVING CELLS IN VITRO 
 
Kvitko O., Koneva I., Sheiko Y., Nina A. Balashenko N., Sapun A, Dromashko S. 
Institute of Genetics and Cytology, Akademicheskaya 27, 220072 Minsk, Belarus 
e-mail: o.kvitko@igc.bas-net.by 
 
Time-lapse microscopy of living cells (TLMLC) is intended for photographing cells and 
subcellular structures at discrete time intervals. This experimental approach allows to study the 
dynamics of different cellular events and insures an efficient data-mining in comparison with 
experiments using fixed (“dead”) cytological specimens.  Time periods of TLMLC experiments and 
their technical details are defined by the process under investigation. For monitoring intracellular 
events relatively short times (minutes – hours) are used, and fluorescent molecular analysis may be 
applied. However, long periods of uninterrupted cell monitoring are necessary for analyzing such 
processes as formation of cell clones and changes of locomotor activity, shape and size of cells 
during ageing. In long-term experiments application of fluorescent imaging is problematic due to 
harmful effects on cells of dyes and excitation light. 
In our study videomicroscopy of  living cells was used for understanding the cause of 
differences of lifespans and cancer transformation in man and mouse [5]. The man and mouse are 
mammalian species with great differences in lifespan and the rate of development of cancer 
diseases. The detailed comparison of human and mouse somatic cells in the context of ageing and 
cancer transformation can be achieved by study of individual cells and cell clones with the 
computerized videomicroscopy of living cell cultures. The analysis of videofilms revealed the 
prominent difference between human and mouse fibroblasts. In mouse big cells (up to 8000 mkm2) 
entered mitotic division as frequently as smaller cells. In contrast, in human cell cultures only small  
cells (whose area did not exceed 2300 mkm2) divided. The cell size increase is typical for cellular 
ageing, and genomic damage accumulates in aged cells. In particular, at least some big cells may be 
polyploids which can produce aneuploid progeny. In mouse we found out the process of a fast cell 
rounding without a following  mitotic division but with a subsequent spreading and cell size 
increase. This process may be connected with replication of DNA without division, i.e. with 
polyploidization. It is possible that in man there is a relatively more strict system of blocking of 
mitotic divisions in abnormal cells, including big polyploid and aneuploid cells. This blocking 
system  retards the accumulation of dysfunctional (aged) as well as transformed cells. It can be one 
of the reasons of the lower rate of cellular and organismal ageing and later development of cancer in 
man in comparison with rodents. 
In another study we employed real-time imaging of living cells  for investigating the  
mechanisms of self-renewal of immortal cell populations. The causes of the indefinite propagation 
of immortalized cell populations remain insufficiently understood, that hinders the research of such  
fundamental processes as ageing and cancer. In our study the interrelations between clonal 
proliferation and abnormalities of mitotic divisions in the immortalized cell line established from  
the mouse embryo  were investigated. 3 mitoses with three daughter cells and 7 asymmetric mitoses 
which generated two daughter cells of conspicuously different sizes were registered among 71 
mitotic divisions in the  individual cell genealogy. Abnormal mitotic divisions either did not slow 
the proliferation  in cell clones compared with progenies of cells that divided by means of normal 
mitoses or were followed by the acceleration of divisions in consecutive cell generations.  These 
data suggest that abnormal mitotic divisions may contribute to the maintenance of the immortalized 
state of cell populations by means of generating chromosomal instability.   
We also used computer videomicroscopy of live cells for establishing the cell line from 
human hair follicles and selection of culture conditions that induce a symmetrical neural 
differentiation of these cells. 
In cooperation with the Minsk-based plant “Planar” we created a new computer 
videcomplex “Tsitomir” which performs a simultaneous videorecording of many areas of cell 
culture. The videocomplex can find broad application in biotechnological research.