The detection of myoglobin in urine and its distinction from normal and variant haemoglobins.

Victims of severe injuries frequently pass haemoglobin, myoglobin, or both proteins in their urine. If the kidneys of such persons are to be considered as donor material for transplantation, a pathology department may be requested to identify which of these pigments is present. If freshly passed urine is available, haemoglobinuria in the absence of myoglobinuria may be rapidly identified by spectroscopy. However, the rapid degradation of myoglobin to the met-myoglobin form will make spectroscopic recognition of this pigment in the urine unreliable. In the absence of variant haemoglobins, myoglobin may be easily distinguished from normal haemoglobin by routine electrophoresis on paper, starch gel, or cellulose acetate at alkaline pH. The electrophoretic method of choice in the presence of variant haemoglobins utilizes polyacrylamide gel at 12 g/100 ml as a supporting medium. At this concentration, the migration both of haemoglobin and its variants is sufficiently retarded to allow the easy recognition of myoglobin.