or PBS, respectively. After being
washed three times in PBS, the sections were incubated with
a 1:50 dilution of FITC-labeled anti-mouse IgG (Santa Cruz,
USA), and the nuclei were stained with propidium iodide (PI)
at 37 °C for 15 min. After being washed five times in PBS, the
sections were examined under a fluorescent microscope
(Olympus, Japan) (Liu et al. 2015a).