ELECTROLYTIC RESISTANCE OF THE BLOOD CLOT

Abstract

This method for the detn. of the electrolytic resistance of the blood clot requires the introduction of platinum electrodes into freshly drawn whole blood. The blood then clots about the electrodes. The electrodes are connected into an alternating current bridge and the changes in the resistance which occur are recorded by a recording galvanometer. This permits the automatic registration of the resistance for periods of 48 hrs. Comparative studies of electrodes made of circular sheet platinum and wire loops indicate that the wire electrodes furnish a better anchor for the clot. An analysis of the current flow between the electrodes shows that precautions must be taken to prevent any large flow of current occurring through the serum surrounding the blood clot. Loss of current, and consequently accuracy, is kept at a minimum by making the electrodes small in comparison to the size of the blood sample. When the spherical volume of the blood sample is 8.5 or more times that of the electrodes the error in the detn. of the clot resistance is kept down below about 10%. Another factor of importance is that there be a minimum of adhesion of the blood to the blood cell walls. This can best be accomplished by coating the cell with Dri-film no. 9987. Comparative tests with this substance and other silicone compounds show that the clot resistances with this substance are highest and most consistent.