The terms PBMC and buffy coat are sometimes used like synonyms. But there is a difference between them: PBMCs are won by density centrifugation with a medium. They are pure leukocyte suspensions, without granulocytes. Buffy Coat however, is won by centrifugation with a filter, so that most erythrocytes are extracted. That means, in a buffy coat there are still granulocytes, lymphocytes and some erythrocytes included. Because of the different composition of these two materials, we recommend different cell separation protocols:
The different sample materials require divergent treatment. For example, tissue requires more strainers because tissue usually requires pre-filtering. Similarly, buffy coat requires a special stabilization buffer.
pluriSpin beads are polystyrene particles that have undergone specific surface modification. Thus, they are biocompatible for cells and show a good mass density which is important for effective incubation with the sample.
Yes. Since pluriSpin is a non magnetic negative isolation method, the untouched target cells are not labeled with beads or antibodies in any way. Thus, after separating your cells with pluriSpin you can use any magnetic system for a further isolation or depletion to enrich or deplete a sub-population, e.g. you can isolate CD25 (Treg cells) from CD4 (T-cell).
The pluriSpin separations beads developed by pluriSelect are not magnetic! The isolation technology is based on the depletion of unwanted cell by the pluriSpin beads in combination with a density gradient centrifugation. It is comparable with the Rosettesep™ technology from the company of Stemcell Technologies® and can be used directly in whole blood, buffy coat, bone marrow or cord blood.
Another chance for the negative isolation is the use of magnetic beads. For this you first have to prepare PBMC via density gradient centrifugation and then you can deplete the unwanted cell populations.
The pluriSelect technology, pluriSpin, is based on the specific depletion of cells with the help of plastic (polystyrene) beads coated with antibodies in combination with a density gradient centrifugation (Leuko Spin Media, Ficoll®, Leucoprep®, Biocoll® ect). Target cells bind to the surface of the pluriSpin beads. During the density gradient centrifugation the pluriSpin beads will go through the gradient and will pull the “unwanted” cells with them.
There is no need for sample preparation (e.g. density gradient) or centrifugation. pluriSpin can be used cooled or at room temperature. Cell separation with pluriSpin is very fast isolation method for untouched cells. You can isolate more than 5 targets from one sample. The technology can be combined with other available systems, such as magnetic cell isolation technology. pluriSpin Beads and density gradient media is all you need for the cell separation. Thus, no extra tools are needed and no extra costs arise.