Ficoll

Ficoll is a neutral, highly branched, high-mass, hydrophilic polysaccharide which dissolves readily in aqueous solutions. Ficoll radii range from 2-7 nm. It is prepared by reaction of the polysaccharide with epichlorohydrin. Ficoll is a registered trademark owned by GE Healthcare companies.

Ficoll is part of Ficoll-Paque, which is used in biology laboratories to separate blood to its components (erythrocytes, leukocytes etc.). Ficoll-Paque is normally placed at the bottom of a conical tube, and blood is then slowly layered above Ficoll-Paque. After being centrifuged, the following layers will be visible in the conical tube, from top to bottom: plasma and other constituents, a layer of mono-nuclear cells called buffy coat (PBMC/MNC), Ficoll-Paque, and erythrocytes & granulocytes which should be present in pellet form. This separation allows easy harvest of PBMCs. Note that some red blood cell trapping (presence of erythrocytes & granulocytes) may occur in the PBMC or Ficoll-Paque layer. Major blood clotting may sometimes occur in the PBMC layer. Ethylene diamine tetra-acetate (EDTA) and heparin are commonly used in conjunction with Ficoll-Paque(TM) to prevent clotting and is used as a mononuclear cell separator.

At one time, fairly early in the research for diabetes treatment by transplantation, Ficoll was used in an attempt to separate islets of Langerhans from enzyme (collagenase) digested human pancreatic tissue. The theory was that separated islets could then be used for transplantation into patients with type 1 diabetes. In practice, using Ficoll led to difficulty obtaining a pure enough preparation of islets, with enough islet recovery from the original tissue, for safe and effective islet transplantation in humans.

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