Exposure of mouse and elephant hemoglobins to each other in acid solution is accompanied by splitting of the molecules, with peptide chains of one migrating to the other. The result is a hybrid of which striking examples have been prepared, some between human and animal hemoglobins, a few between those of such distantly related species as frog and elephant. The hybridization is not a random occurrence; attempts at production of new varieties fail more often than they succeed. The resulting hybrid hemoglobins can be identified by fingerprinting with vertical starch-gel electrophoresis supplemented with paper chromatography and are composed of reasonable stable molecules.
Man once had a single hemoglobin; he now has four, plus numerous varieties of abnormal hemoglobins, identified by wandering amino acides within the peptide linkage. Four polypeptide chains may soon acquire a fifth embryonic member of the family. Many of the abnormal hemoglobins, as well as normal ones,