Sedimentation field-flow-fractionation: emergence of a new cell separation methodology.

Field flow fractionation (FFF) methods were conceptualised in the late 1960s by J.C Giddings. These techniques are particularly suited for the retention and separation of micron and sub-micron sized particles. Systematic technological development as well as methodological procedures were established to achieve separations over the last 30 years. The elution mechanism of micron sized species is now known as 'steric/hyperlayer'. Cells are micron sized particles of life science interest, in particular those living in suspension. The separation of cells according to differences in their biophysical characteristics is therefore possible using the FFF principle. In the first part of this report, characteristics of classical cell separation methodologies are recounted as well as the specific features of FFF. In the second part, a review of cell separations or purifications obtained with sedimentation FFF techniques is given and FFF trends in cell separation is developed.