2.14. BGNP Uptake by Confocal Microscopy

Following the cell treatment, cells were fixed on 12-mm glass coverslips with 4% paraformaldehyde (PFA) in PBS for 15 min at RT, then washed three times with PBS. The coverslips were mounted with an antifade mounting medium (vectashield H-1000, Vector Laboratories, Burlingame, CA, USA) on a glass microscopy slide. Images were acquired by a confocal microscope (Leica SP8 TCS, Leica Microsystems GmbH, Wetzlar, Germany) with 63× and 100× oil immersion objectives. Z-stacks were acquired by using a 1024 × 1024 scan format and 400 msec speed.