Demonstration of haemoglobin associated with isolated, purified spectrin from senescent human red cells.

Employing a direct and sensitive radioimmunoassay (RIA) we have confirmed the presence of haemoglobin associated with isolated, purified spectrin from senescent red cells. Haemoglobin associated with spectrin occurs in the highest amount in cells with an MCHC greater than 36 g/dl and is approximately 3% of the total spectrin extract. Spectrin from the young cells had the least haemoglobin, while an intermediate amount was found in unfractionated, whole red cells. The RIA results were in close approximation with estimation of the haemoglobin-spectrin complex obtained by carefully integrating the Coomassie blue stain profiles from 4% SDS PAGE in densitometric scans from isolated spectrin.