2.5.1. Evaluation of the Chromosomal aberrations (CAs) and the Mitotic Index (MI)
BM cells were prepared according to the colchicine-hypotonic citrate technique for CAs. Briefly, 2 hours before sacrifice, rats were IP-injected with colchicine (2mg/kg BW); the femur bone of each animal was taken and cleaned from tissues and muscles, and then the femoral marrow was flushed out using (0.075M) potassium chloride into a centrifuge tube and centrifuged at 2000rpm for 10minutes. Additionally, the cells pellets were fixed in (1:3) acetic acid/methanol (v/v), which was repeated three times; then the cell suspension was dropped on coded and sterile cleaned frosted slides and then dried followed by staining with 10% Giemsa stain; and finally, the slides were examined under a light microscope (Japan, Meiji). The frequency of CAs was scored in at least 100 meta-phase plates per animal; moreover, the chromatid -gaps and -break chromosome gaps and breaks, ring, deletion and exchanges were recorded; and the MI was obtained by counting at least 1000 cells per animal for dividing cells (18) (19).