Free-flow electrophoresis

FFE is an analogous technique to capillary electrophoresis, with a comparable resolution, that can be used for scientific questions, where semi-preparative and preparative amounts of samples are needed.

Because of the versatility of the technique, a wide range of protocols for the separation of samples like rare metal ions, protein isoforms, multiprotein complexes, peptides, organelles, cells, DNA origami, blood serum and nanoparticles exist.

The advantage of FFE is the fast and gentle separation of samples dissolved in a liquid solvent without any need of a matrix, like polyacrylamide in gel electrophoresis.

[3] As flow cytometry became the standard method for cell sorting, FFE developments focused on the separation of proteins and charged particles.

[5] Afterwards the samples can be characterized by all major techniques like HPLC, LC-MS, mass spectrometry (ESI / MALDI, depending on the protocol used) or electrophoresis (IEF / SDS PAGE, 2D-PAGE).

Typically concentrations of urea up to 8M, 0.1–1% of detergents like: CHAPS, CHAPSO, Digitonin, Dodecyl-ß-D-maltoside, Octyl-ß-D-glucoside, Triton-X-114 (IEF) and DTT up to 50 mM are tolerated.