For cytofluorimetric analysis adherent cells were trypsinized, then washed twice in PBS, incubated with 5 μl of fluorochrome-conjugated antibodies for 30 min at 4 °C (5 × 10
5cells/FACS tube), fixed with 1% formaldehyde solutions for 5 min at 4 °C, centrifuged for 5 min at 1600 rpm and washed once with 1 ml of PBS for 5 min at 1600 rpm.
CD133/2 (293C3) (Miltenyi Biotec, Bergisch Gladbach, Germany),
HLA-I, NGF-R,
ICAM-1, CD20,
CXCR4, CD10, c-Kit antibodies (all from BD Biosciences, Franklin Lakes, NJ, USA) conjugated with different fluorescent dyes were used; the unconjugated antibodies
Nestin (Novus Biologicals, Minneapolis, USA) and Melan-A/MART-1 (Santa Cruz Biotechnology, Dallas, TX, USA) were used in combination of the goat-anti-mouse IgG-FITC (BD Biosciences) as secondary antibody and used after cell permeabilization. For apoptosis analysis cells were trypsinized, washed in PBS, fixed with 70% ethanol for 45 min at 4 °C, washed in PBS and stained with propidium iodide (50 μg/ml diluted in PBS) and RNAase (250 μg/ml), then stored for at least 3 h at 4 °C before analysis. Flow cytometer analysis was performed by
BD FACScan™ System using CellQuest Pro software on a minimum of 5000 events for each sample.
Argaw-Denboba A., Balestrieri E., Serafino A., Cipriani C., Bucci I., Sorrentino R., Sciamanna I., Gambacurta A., Sinibaldi-Vallebona P, & Matteucci C. (2017). HERV-K activation is strictly required to sustain CD133+ melanoma cells with stemness features. Journal of Experimental & Clinical Cancer Research : CR, 36, 20.