Ficoll-Paque™ PLUS media is a ready-to-use aqueous medium for density gradient centrifugation. The media was developed for large- and small-scale purification of mononuclear cells from human peripheral blood. Protocols for purifying mononuclear cells from sources other than human peripheral blood have also been developed (see data file for references and details).

The Ficoll-Paque™ PLUS density gradient media has a density of 1.077 ± 0.001 g/mL at 20°C, which is optimized for the isolation of mononuclear cells from human blood. If densities other than 1.077 g/mL are required for optimal separation, Cytiva also offers gradient media of densities 1.073 g/mL (Ficoll-Paque PREMIUM 1.073), and 1.084 g/mL (Ficoll-Paque PREMIUM 1.084). An alternative is Percoll™ PLUS density gradient medium that forms iso-osmotic gradients within a density range of 1.0 to 1.3 g/mL.

Mononuclear cell isolation using Ficoll-Paque™ media is based on simple and rapid centrifugation methodology developed by Bøyum. Defibrinated or anticoagulant-treated blood is diluted with an equal volume of a balanced salt solution, layered carefully over Ficoll-Paque product (without intermixing) and centrifuged for 30 to 40 min (see Instructions for Use for more information).

Differential migration of cells during centrifugation results in the formation of layers containing different cell types. The bottom layer contains erythrocytes, which aggregate in Ficoll-Paque™ media at room temperature and sediment completely. The intermediate layer mostly contains granulocytes as a result of their increased density after contact with the slightly hypertonic Ficoll-Raque™ media. Lymphocytes, monocytes, and platelets are not dense enough to penetrate the Ficoll-Paque media and therefore collect in a concentrated band between the media and the blood plasma.

Ficoll-Paque products should be stored between 4 °C and 30 °C and protected from light, under which conditions they will maintain sterility and stability for 3 years.