Fluorescent cytoplasm and Heinz bodies of koln erythrocytes; evidence for intracellular heme catabolism.

Hb, Koln, one of the common mutant hemoglobins responsible for unstable hemoglobin disease, was found to catabolize a fluorescent yellow pigment (FYP) in circulating erythrocytes. FYP is responsible for the fluorescence observed in the cytoplasm as well as in the Heinz bodies of Koln RBC. Front face fluorometry and fluorescence microscopy showed that Heinz bodies emit 10- 20 percent of the RBC's fluorescence.