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
Clotting time Clotting time Clotting time is the time required for a sample of blood to coagulate in vitro under standard conditions. There are various methods for determining the clotting time, the most common being the capillary tube method. It is affected by calcium ion levels and many diseases. Normal value of clotting time is 8 to 15 minutes. For the measurement of clotting time by test tube method, blood is placed in a glass test tube and kept at 37° C. The required time is measured for the blood to clot. There are several other methods, including testing for those on