Field flow fractionation in biomedical analysis.

Samples of biomedical interest which have been analysed by field-flow fractionation techniques are surveyed. The list begins with whole cells and microorganisms, going through viruses, nucleic acids, cell fragments and organelles, down to proteins and their aggregates. The principles of separation in the normal and steric mode of retention are illustrated, and instrumentation and techniques are described. The review concentrates mainly on the two systems of choice for biomedical applications: sedimentation and flow field-flow fractionation.