Adaptation of the Standard Durrum-Typc Cell for Reverse-Flaw Paper Electrophoresis

Abstract

Although determination of the concentration of protein-bound iodine (PBI) in serum has proved useful in clinical medicine and research, interpretation of the results often remains difficult because of the lack of simultaneously obtained data on the thyroxine-binding capacity of the serum. Thus, in a euthyroid person, pregnancy or the administration of estrogens may cause an increase in the serum PBI concentration to a level suggesting hyperthyroidism. Determination of the thyroxine-binding capacity of the serum in such instances will reveal that the latter is elevated and that the serum PBI concentration reflects an increased concentration of bound thyroxine. Therefore, the development in recent years of paper electrophoresis methods for determining the thyroxine-binding capacity of the serum has been a significant advance and has provided much useful data; 7 however, for reasons discussed below, standard electrophoresis technic has suffered from certain disadvantages in the determination of thyroxine-binding capacity. Ingbar has succeeded in overcoming these disadvantages by substituting tris-maleate for barbital buffer, whereas Robbins has overcome them by means of a reverse-flow technic, using specially constructed apparatus. Tanaka and Starr have reported the similar use of reverse-flow electrophoresis, but details of the technic were not given. Both Robbins and Tanaka described the