title: YOPRO-1 permits cytofluorometric analysis of programmed cell death (apoptosis) without interfering with cell viability.
abstract: In the absence of cell permeabilization, the impermeant nuclear dye YOPRO-1 permits accurate analysis of apoptosis using cytofluorometry or fluorescent microscopy. Several immune cell populations were studied including dexamethasone-treated thymocytes, irradiated peripheral blood mononuclear cells and a growth factor-depleted tumor B cell line. Excellent correlation values were found with acridine orange using cytofluorometry and with eosin-hematoxylin using optical microscopy. Under fluorescent microscopy, YOPRO-1-fluorescent cells demonstrate the morphological features of cells undergoing apoptosis such as nuclear shrinkage and fragmentation. An important characteristic of the dye that differs from all other nuclear dyes previously used for the detection of apoptosis is that it does not label living cells. Cell sorting after flow cytofluorometry analysis confirmed that only the apoptotic cell population was labelled with YOPRO-1. Further studies showed that while incubation of living cells with Hoechst 33342 almost completely abrogated the capacity of T cells to proliferate in response to several stimuli, YOPRO-1 had no inhibitory effect. This new simple, rapid and reproducible use of the YOPRO-1 dye should prove useful in the analysis of apoptotic cells as well as for investigations of the functional properties of living cells in a culture containing apoptotic cells.
authors.affiliation: INSERM U415, Pathogénèse du Sida et des Infections à Tropisme Immunitaire et Nerveux, Institut Pasteur, Lille, France.
authors.forename: T
authors.initials: T
authors.lastname: Idziorek
authors.forename: J
authors.initials: J
authors.lastname: Estaquier
authors.forename: F
authors.initials: F
authors.lastname: De Bels
authors.forename: J C
authors.initials: JC
authors.lastname: Ameisen
mesh_terms: D000165:Acridine Orange; D000818:Animals; D017209:Apoptosis; D001583:Benzoxazoles; D002460:Cell Line; D002469:Cell Separation; D002470:Cell Survival; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006801:Humans; D007223:Infant; D008213:Lymphocyte Activation; D051379:Mice; D011806:Quinolinium Compounds; D013601:T-Lymphocytes / Q000166:cytology; D013950:Thymus Gland / Q000166:cytology
chemical_list: D001583:Benzoxazoles; D005456:Fluorescent Dyes; D011806:Quinolinium Compounds; C089813:YO-PRO 1; D000165:Acridine Orange