4.10. Flow Cytometry

For investigation of cellular uptake of LL-37, 1 × 10⁶ macrophages were seeded in a 24-well plate and incubated with LL-37-TAMRA (11 µM) for 30 min at 4 °C or room temperature, respectively. Afterwards, cells were harvested using EDTA (1 mM, Sigma-Aldrich, Steinheim, Germany) and transferred into FACS tubes (Falcon, Corning, Corning, NY, USA). Followed by centrifugation at 1300 rpm for 10 min, cells were subsequently washed once with FACS buffer (PBS, 10% sodium azide, 10% FCS). Samples were then measured using a FACS Calibur (BD Biosciences, Franklin Lakes, NJ, USA) and analyzed with FlowJo v10.4.1 (BD, Franklin Lakes, NJ, USA).