PBMCs

A density gradient media, such as Ficoll-Paque, is used to separate the whole blood into the following components: plasma, buffy coat (mononuclear cell rich fraction), and red blood cells. When utilizing this method, the whole blood is added to the conical tube and then the density gradient media is gently added below the blood.

When this method is employed, the density gradient, such as Ficoll-Paque, is placed at the bottom of the conical tube and then the whole blood sample is gently layered above the media. 

The SepMate method utilizes a SepMate^TM tube that contains an insert which creates a barrier between the density gradient media and the whole blood. Similarly, the Leucosep method utilizes a special tube that contains a physical porous barrier. This allows the whole blood to be layered above the density gradient media more quickly than with traditional methods, such as underlay and overlay. The centrifuge time for these methods is shorter, resulting in more efficient PBMC isolation.