pEYFP-Nuc vector is a useful tool for three-dimensional and time-lapse observation of nuclear morphology of Jurkat cells during apoptosis.

Using a pEYFP-Nuc vector, which contains nucleic acid sequences of a nuclear localization signal, we established a Jurkat-YN cell line that expressed enhanced yellow fluorescent protein (EYFP) in the nucleus. We observed three-dimensional and time-lapse changes in nuclear morphology of Jurkat-YN cells during Fas-induced apoptosis using a confocal laser scanning microscope. The nuclear forms visualized by EYFP were almost equal in quality to those visualized by SYTO59, a nucleic acid stain for living cells. Three-dimensional deformities in the nuclear form were observed during apoptosis before chromatin condensation became apparent, indicating these deformities are characteristic morphological changes of the early stage of apoptosis. In conclusion, the pEYFP-Nuc vector is a useful tool in the time-lapse observation of nuclear morphology of living cells during apoptosis.