| Abstrakt: |
The preparation of extracts from pregnant mare serum presents a problem different from that found in the extraction of pituitary gland material. The main difficulty is found in the solubility of serum proteins which form colloidal solutions and cannot easily be separated from the gonad stimulating factor itself. Such solutions appear opalescent or turbid and pass through a bacteria-proof filter only at a very slow rate. The method as described by Evans, Gustus and Simpson1overcomes this difficulty by adsorbing the active principle on aluminum hydroxide. This method yields a highly purified product, but requires special equipment not available in every laboratory.Following is a rather simple method which gives a product suitable for biological and clinical use.Serum from pregnant mares was precipitated in the usual way with 2 volumes of acetone, washed with acetone and dried. This precipitate formed the raw material used in the preparation of the extract. The powder was treated with a 6% solution of butyl alcohol in water, as described for pituitary gland extraction.2It is doubtful whether the addition of butanol, advantageous in the extraction of the pituitary gland, is of any particular value in this case, since the serum quickly swells up in water and does not present any problem as far as extraction is concerned. However, the slightly antiseptic properties of the butyl alcohol, which prevent putrefaction during the process of extraction at room temperature, made it desirable to apply this method to serum also. |
