I tried using 100ng/ml media concentration based on the literature from Breast cell lines similar to HMEC. I checked for phosphorylated H2AX and p-chk2 to quantify DNA damage through Western Blots. I could see same intensity band for both treated and untreated whereas there is no expression of p-ChK2 in the NCS and Untreated cells alike. I would like to know what might cause this problem and what types of cell lines are sensitive to NCS treatment.