Is Ferratin Precipitinogenic?

Abstract

In 1893 Schmiedeberg 1 announced that it was possible to extract a protein from the liver by means of boiling water. The extract was filtered and the filtrate treated with tartaric acid for precipitation of the protein. Schmiedeberg concluded that this was a high iron containing protein but not a nucleoprotein. He named it ferratin. Subsequent investigators, 2 however, came to the conclusion that the protein extracted in this fashion was really a nucleoprotein, or derived from nucleoprotein.

Since by repeated extraction and precipitation it seemed probable that ferratin could be completely separated from the accompanying blood and lymph proteins, it seemed advisable to test its antigenic properties.

Our first experiment was unsuccessful and new ferratin was prepared with particular care to avoid its exposure to any undue hydroxyl ion concentration. In dissolving the ferratin it was suspended in water and 0.5% sodium carbonate solution was added slowly with constant stirring in such quantities that the solution showed only the faintest reaction to litmus. No attempt was made to dissolve completely all the suspended material and the undissolved portion was removed by filtration.

Numerous experiments were made to determine whether ferratin is precipitinogenic. As the rule 2, 4, 6, 8, 10 or 12 cc. of the 1% solution of ferratin were introduced intravenously in rabbits at intervals of 3 or 4 days and on the fourth day after the last injection the serum was tested for precipitin by the contact or layer method.