Analysis of DNA fragmentation was performed with the cell
death detection enzyme-linked immunosorbent assay (ELISA) kit
based on the photometric sandwich immunoassay of cytoplasmic
histone associated DNA fragments (Roche Molecular Biochemicals,
Indianapolis, IN), using manufacturer’s recommended protocols.
After addition of substrate for peroxidase, the spectrophotometric
absorbance of the samples was determined using a plate reader at
a test wavelength of 405 nm. OD value was utilized to reflect cell
apoptosis.