The cells were harvested by adding 1 ml/well of trypsin to
separate adherent cells and then 3 ml/well of SFM to stop
the effect of trypsin and harvest the cells. The cells were subsequently
centrifuged at 1500 rpm for 10 min. Each pellet was
washed with PBS and then centrifuged, as above, and the process
was repeated. The resultant pellets were stored at 20 C
until the time of DNA extraction.
DNA from both types of cells was extracted and purified
using a DNA extraction kit (Qiagen, Chatsworth, CA, USA)
according to the manufacturer’s protocol. The resultant purified
DNA was stored at 20 C until DNA electrophoresis.
Isolated DNA samples were subjected to electrophoresis on
a 0.8% agarose gel for 45 min at 100 volt. The gel was visualized
under UV light following ethidium bromide staining to
determine DNA fragmentation.