Argon krypton laser

In vitro cellular uptake was carried out using FITC-BSA-conjugated BCmFs in macrophage-differentiated U937 cell lines on four-well glass chamber slides (Niikura et al. 2013 (link)). Macrophage differentiated U937 cells were incubated with BCmFs-BSA-FITC (250 and 500 µg/ml) and as control with BSA-FITC (500 µg/ml), BCmFs, and medium. After incubation, cells were washed three times with PBS, incubated with methanol for 5 min and then with acetone for 30 s for fixation. The sample was dried at room temperature and stained with DAPI Fluoromount-G (6-diamidino-2-phenylindole) for 90 min at 37 °C, then observed using a Confocal Laser Scanning Microscope (CLSM) (Zeiss LSM 880, Germany). CLSM images were obtained by scanning contrasting double-labelled specimens using a Zeiss Confocal LSM880 microscope equipped with an Argon-Krypton laser (Carl Zeiss Micro-imaging, Inc., NY, USA). Images captured with DAPI and FITC were overlaid to determine the localization and co-localization of fluorescent microparticles and cells.