The main protein in the blood, albumin constitutes 50 to 65% of the proteins in the blood plasma (liquid part of the blood). Soluble in water and made by the liver, it is not part of the globulins which are the other proteins in the blood. Its level, called albuminemia, is about 40 grams per litre of blood. Albumin is also found in egg (ovalbumin) and milk (lactalbumin).