Serum iron in other molecules in cells throughout the body. None of this iron is directly accessible by testing the serum. However, some iron is circulating in the serum. Transferrin is a molecule produced by the liver that binds one or two iron(III) ions, i.e. ferric iron, Fe; transferrin is essential if stored iron is to be moved and used. Most of the time, about 30% of the available sites on the transferrin molecule are filled. The test for serum iron uses blood drawn from veins to measure the iron molecules that are bound to transferrin, and circulating in the blood. The
Blood, toil, tears, and sweat Blood, toil, tears, and sweat The phrase "blood, toil, tears and sweat" became famous in a speech given by Winston Churchill to the House of Commons of the Parliament of the United Kingdom on 13 May 1940. This was Churchill's first speech on 13 May 1940 to the House of Commons after having been offered the King's commission the previous Friday, to become Prime Minister of the United Kingdom in the first year of World War II. Churchill had replaced Neville Chamberlain on 10 May, and in this speech he asked the House to declare its confidence in his Government.