BACKGROUND: To study the apoptotic process in time, we used the following flow cytometric (FCM) techniques: phosphatidylserine (PS) translocation by @entity4404 (AnV), DNA fragmentation by in situ end labeling (ISEL), and propidium iodide (PI) staining. Because PS translocation is assumed to be an early feature of @entity204 ( @entity204 ), we questioned if AnV positivity implies inevitable cell death. METHODS: Apoptosis was induced in Jurkat cells by gamma-irradiation, incubation with camptothecin (CPT), or cytosine beta-D-arabinofuranoside (Ara-C). At different time intervals, @entity204 was quantified by AnV/PI and ISEL. To analyze the influence of cell handling procedures on @entity204 , we applied these three FCM techniques on @entity2280 + bone marrow (BM) stem cells after selection and after a freeze-thaw procedure. Various AnV/PI- @entity2280 + fractions were cultured in a single-cell single-well (SCSW) assay. RESULTS: Jurkat cells under three different detrimental conditions showed essentially the same pattern of apoptosis in time. Initially developed AnV+/PI- cells subsequently (within 1 h) showed ISEL positivity, after which they turned into AnV+/PI++ cells with even higher levels of ISEL positivity (80-90%). Eventually, they lost some of their PI and ISEL positivity and formed the AnV+/PI+ fraction. Cell handling of @entity2280 + cells caused high and variable AnV+/PI- fractions (overall range 23-62%). Within total AnV+ and AnV+/PI- populations, only a minority of @entity2280 + cells showed ISEL positivity (range 4-8% and 0.8-6%, respectively). Different fractions of AnV+/PI- @entity2280 + cells did have clonogenic capacity. CONCLUSIONS: @entity204 of cell suspensions in vitro can be followed accurately in time by these three FCM techniques. PS translocation is followed rapidly (within 1 h) by oligo-nucleosomal DNA fragmentation, after which cell (and nuclear) membrane leakage occurs. Detection of PS asymmetry by AnV-fluorescein isothiocyanate (FITC) is not always associated with (inevitable) apoptosis, as can be concluded from the proliferative capacity of AnV+ /PI- @entity2280 + cells in the SCSW assay.

The dynamic process of apoptosis analyzed by flow cytometry using XXXX /propidium iodide and a modified in situ end labeling technique.

@entity4404 :: ('308', 'Gene') :: ['Annexin-V'] @entity2280 :: ('947', 'Gene') :: ['CD34'] @entity204 :: ('MESH:D003643', 'Disease') :: ['programmed cell death', 'PCD']
@entity4404 :: (308,Gene) :: ['Annexin-V']
