Hematoxylin-eosin staining of placental arterioles
After fixation, the placental arterioles were dehydrated by an ethanol gradient and cleared with xylene. The transparent tissue blocks were embedded in melted paraffin, and the tissue blocks were then sliced and baked after being cooled and solidified. The dried slices were dewaxed by xylene, dehydrated by gradient ethanol, stained by hematoxylin and eosin and finally dehydrated, made transparent, sealed and imaged.