SENS PubMed Publication Search
Flow Cytometry-based Method for Efficient Sorting of Senescent Cells
Erwan Goy 1, Nathalie Martin 1, Claire Drullion 1, Laure Saas 1, Olivier Molendi-Coste 2, Laurent Pineau 2, David Dombrowicz 2, Emeric Deruy 1, Hélène Bauderlique-Le-Roy 3, Olivier Samyn 1, Yvan De Launoit 1, Corinne Abbadie 1
...Here, we describe a flow cytometry strategy for sorting senescent cells according to three senescence canonical markers whose thresholds can be independently adapted to be more or less stringent: (i) the senescence-associated-β-galactosidase (SA-β-Gal) activity, detected using 5-dodecanoylaminofluorescein Di-β-D-galactopyranoside (C12FDG), a fluorigenic substrate of β-galactosidase; (ii) cell size, proportional to the forward scatter value, since increased size is one of the major changes observed in senescent cells; and (iii) cell granularity, proportional to the side scatter value, which reflects the accumulation of aggregates, lysosomes, and altered mitochondria in senescent cells. We applied this protocol to the sorting of normal human fibroblasts at the replicative senescence plateau. We highlighted the challenge of sorting these senescent cells because of their large sizes, and established that it requires using sorters equipped with a nozzle of an unusually large diameter: at least 200 µm. We present evidence of the sorting efficiency and sorted cell viability, as well as of the senescent nature of the sorted cells, confirmed by the detection of other senescence markers, including the expression of the CKI p21 and the presence of 53BP1 DNA damage foci. Our protocol makes it possible, for the first time, to sort senescent cells from contaminating proliferating cells and, at the same time, to sort subpopulations of senescent cells featuring senescent markers to different extents.