Summary: Model of Human Hemoglobin. Imagine the days when theses and dissertations were required to be written in Latin. In his 1825 Commentatio de vera materiae sanguini purpureum colorem impertientis natura, Johann Friederich Engelhart proposed the molecular mass of hemoglobin to be an astonishingly large 16000 Daltons per iron. No respectable scientist of the time believed that molecules could be that large. We now know that hemoglobin has a mass of ~64000 Daltons, is the major oxygen-carrying component of blood, and can bind with glucose to form glycated hemoglobin (most commonly measured as Hb A1c). Because Hb A1c is routinely measured for diagnosing diabetes and prediabetes, as well as monitoring mean glycemia, it is important that Hb A1c results be reliable. But how well do existing Hb A1c assays perform? This month's issue of Clinical Chemistry contains the results from 2 studies of Hb A1c assay performance, plus an accompanying editorial that discusses both of the studies.
