The testes of busulfan-treated mice were fixed in Bouin solution
and embedded in paraffin. Sections of 5-mm thickness were stained
with hematoxylin and eosin and observed under a light microscope
[12]. For measurement of seminiferous tubule diameter, images of
the testis sections were acquired using a 10 or 4 objective lens
and 50 tubules/section were randomly selected and measured using
the line measure option in the NIS-Elements software (Nikon,
Tokyo, Japan)