It has long been recognized that a treatment for beta hemoglobin chain anomalies could result if a way to reverse the Hb F to Hb A switch in humans were found. Studies of hemoglobin switching have been hampered by the fact that small animals normally used in the laboratory do not have a true Hb F. However, several small animal models which take advantage of a switch in minor beta chain proportions in certain strains of inbred mice and rats have been proposed and used. The use of these models has suffered from what, until now, could be considered technically demanding, time-consuming methodologies. In this study we report an effective, rapid and technically streamlined model of hemoglobin switching utilizing Fisher 344 rats and high performance liquid chromatography with a weakly cationic column.