Astereological analysis of the FRTL-5 cells up to four days after trypsinisation.

FRTL-5 cells grow as a monolayer culture in vitro and they must be detached from the solid surface by trypsin before reseeding. The aim of this study was to examine by light microscopy and by the astereological method the changes that occur in FRTL-5 cells one, two, three or four days after trypsinisation. The most pronounced qualitative and quantitative changes were seen from the first to the second day after trypsinisation, as the area of the cells increased by 119%, their nuclei by 71% and the cytoplasm by 150%, while the nuclear-cytoplasmic ratio decreased by 42%. Significant increases in the average area of the cells, their average nuclear diameter and perimeter were seen also on the third and fourth days, while the average nuclear-cytoplasmic ratio decreased significantly on the first three days after trypsinisation and then remained constant.