Arne Tiselius
Tiselius, Arne (1902-1971) was a Swedish physical chemist who won the 1948 Nobel Prize in chemistry for his research on electrophoresis (a method of separating and purifying through the use of an electric field) and adsorption (a process in which matter gathers on the surface of a material). His work resulted in new methods for accurately analyzing proteins. He also identified individual proteins in blood serum.
Tiselius was born in Stockholm, Sweden, in 1902. He enrolled at the University of Uppsala in 1921, and studied with Swedish chemist Theodor Svedberg, who developed the ultra-centrifuge for determining the molecular weights of large molecules. In 1924, Tiselius graduated with a master's degree in chemistry, physics, and mathematics, and remained at Uppsala, first as Svedberg's research assistant, and in 1930, as assistant professor of chemistry. He remained at Uppsala until his retirement in 1968.
In his early research, rather than using the ultracentrifuge, Tiselius investigated molecular separation by means of electrophoresis. Electrophoresis involves the separation and purification of varying molecules in a solution, based on the fact that molecules of different sizes and electric charges move at different speeds and directions within an electric field. Tiselius improved the method of electrophoretic analysis of proteins and enzymes by employing ultraviolet-light photography, rather than the traditional fluorescent photography. In 1931, he earned his doctorate with his thesis, “The Moving Boundary Method of Studying the Electrophoresis of Proteins.” The paper was a standard reference in the field.
Wanting to improve on his method of separating molecules, Tiselius expanded his research to include biochemistry. Aware that even carefully centrifuged substances can retain impurities that can interfere with precise analysis, he began experimenting with chromatographic analysis. By this method, light of a specific sequence is passed through a substance. Over the course of several experiments, tables are formed that reveal the “chromatic signature” of a particular sample. Tiselius used this method to study the properties of light diffusion through zeolite, a translucent mineral. In 1934, he received a grant from the Rockefeller Foundation and, through 1935, he studied at the Frick Chemical Laboratory at Princeton University. There, he continued the study of chromatographic analysis, and developed a method to accurately quantify the diffusion of water molecules through zeolite crystals.
Upon his return to Uppsala, Tiselius improved on the electrophoretic method he had developed while at Princeton. A U-shaped tube was filled with chemical solvents to which was added a solution containing the sample to be analyzed. A charge was applied at one end, and migrating elements reached the solvents at different stages along the tube. Test samples taken at various points along the path of migration could then be analyzed to determine which of the components had arrived at that point. He used blood plasma and became the first to isolate the three blood proteins known as globulins, which he named alpha, beta, and gamma. He also discovered antibodies, a fourth component found between the beta and gamma globulins. This work became especially valuable during World War II (1939-1945), when it was used for analyzing blood scrum for transfusion purposes.
Tiselius found when polypeptide chains were broken down, the differences in the individual peptides were too subtle for accurate electrophoretic analysis. He incorporated the adsorption method of analysis, which involves flushing a mixture containing a substance with an affinity for absorbing one peptide or another through a tube, then analyzing the wash from the tube to determine the peptides that had been in the original mix. This procedure had a major drawback, though, in that molecules in the wash were often contaminated by other molecules in the solution. This contamination was called tailing.
In 1943, Tiselius developed a new method of adsorption, which eliminated the problem of tailing. This method became known as displacement analysis and involved adding a substance of higher absorption affinity to the solution in the wash. In time, this adsorption technique was used to isolate, purify, and analyze a variety of medically important proteins, including insulin.
In 1938, a special chair in biochemistry was created specifically for Tiselius at the University of Uppsala. He was elected president of the Nobel Foundation in 1960, and established the Nobel Symposium to evaluate the social and ethical effects of award-winning developments.