. Preparation of saline extract from dried placenta
Fresh placenta from recently delivered sheep was cleaned with normal saline and all blood clots were removed. The placenta was then weighed, cut into small pieces and dried in a hot air oven at 40 50°C until a constant weight was obtained The dried placenta was then pulverized in a ceramic mortar and the powder was stored in a desiccator. Ten g aliquots of the powder were extracted at room temperature with 25 ml of normal saline t~r 3 h, after which it was centrifuged at 4800 rev./min for l0 rain. The supernatant was collected and stored in a refrigerator at 4°C. Any volume of the extract, therefore, was easily related to the weight of the powdered placenta and thus to the weight of the fresh placenta. The weight of the extract was expressed as weight of dry placenta which produced that quantity of
extract.