The precise 1 mm tissue thickness was guaranteed with a tissue slicer designed explicitly for this purpose.
In brief, the tissue slicer plate has a 1 × 10 × 10 mm cubic space.
The tissue slicer was put on the surface of ovary. Then another plate (holeless) was placed over the tissue slicer, and the ovary was cut between the slicer and the surface of ovary using a sharp edge.
The cortical ovarian tissue was thus cut into 1 × 10 × 10 mm pieces