Transferrin saturation

Transferrin saturation, abbreviated as TSAT and measured as a percentage, is a medical laboratory value. It is the ratio of serum iron and total iron-binding capacity. Of the transferrin that is available to bind iron, this value tells a clinician how much serum iron are actually bound. For instance, a value of 15% means that 15% of iron-binding sites of transferrin are being occupied by iron. For an explanation of some clinical situations in which this ratio is important, see Total iron-binding capacity. The three results are usually reported together.