Ovotransferrin, also called conalbumin, is a glycoprotein with a molecular weight of 76,000. Ovotransferrin comprises approximately 13% of the protein content of egg albumen. More than sixty years ago, researchers determined that ovotransferrin is an iron-binding protein, making the iron in a bacterial culture medium nutritionally unavailable to potentially harmful micro-organisms, such as Schigella dysenteria (for which iron is an essential nutrient).

These same investigators later determined that a fraction of human blood serum exerts the same iron-binding action as ovotransferrin. This blood serum protein was initially named siderophilin, but today is known as human transferrin. Ovotransferrin and blood transferrin are now known to have similar amino acid compositions (see table), as well as similar carbohydrate content.