Hoechst Staining Study for the Detection of Apoptosis

Cells were seeded in 6-well plates and allowed to adhere for overnight. Then, the cells were incubated with CdSe/ZnS@L-Cys-TAEA-5-FUA (200, 100, 50, 20, and 10 μg/mL) for respective time points and stained with Hoechst 33342 (10 mg/mL) at 37°C for 30 min. The fluorescence images of cells were captured using a fluorescence microscope. The rate of the abnormal (condensed or fragmented) nucleus was obtained by counting eight randomly chosen fields per dish for each experimental group from three independent experiments and expressed as percent apoptotic nuclei. Cell nuclei stained with Hoechst 33342 were observed at a wavelength of 405 nm and emission wavelength between 430 and 480 nm.