Serum protein fractionation by isotachophoresis using amino acid spacers.

Analytical and preparative isotachophoresis has been carried out using amino acids and peptides as discrete spacers in contrast to the usually employed continuous mobility spectrum Ampholine. Analytical isotachoresis in free solution, using the LKB Tachophor, demonstrated the separation of human serum into distinct mobility subgroups, n spacers giving rise to n + 1 protein subgroups. Preparative fractionation on polyacrylamide gel was carried out on the LKB Uniphor using threonine and glycine as spacers. Immunoelectrophoretic analysis showed that eight out of ten proteins assayed were clearly resolved in the three subgroups obtained, thus demonstrating the sharpness of isotachophoretic resolution.