On the preservation in vitro of living erythrocytes

Abstract

The length of life of the functioning red blood cell is not known, but there is indirect evidence that it is several weeks at least. A priori one might suppose that if these elements were kept in the cold outside the body their period of survival would be much longer. But as a matter of fact in citrated plasma or defibrinated blood the erythrocytes of many species begin to break down within a week or ten days; and washed erythrocytes in normal salt solution or Ringer's fluid do not last even so long.

In previous papers we have shown that the early hemolysis of washed erythrocytes is attributable in large part to injury during washing; and that this injury can be prevented by the presence of a very little gelatin in the wash fluid (1/8th of 1 per cent.). But even when protected during washing the erythrocytes do not remain intact in vitro nearly so long as they are supposed to in the circulation. We have addressed ourselves to the problem of their preservation.

For reasons which need not here be entered into, our first experiments were made with solutions of inorganic salts to which non-protein colloids were added. But it was found that though gelatin will protect red cells against injury during washing it has no preservative effect; agar proved toxic, as shown by early laking; and dextrin had only slight preservative qualities, except in concentrations which caused a browning of the blood pigment, presumably to methemoglobin. Soluble starch, the watery extract of coagulated blood serum, beef albumen, an aqueous solution of the alcohol-soluble constituents of blood serum, and even serum water made up to isotonicity with sodium chloride were all nonpreservative.