Effective separation of the PBMCs from the erythrocytes and polymorphonuclear leukocytes (PMNs) requires careful layering of diluted blood samples over Lymphoprep™; this requires some practise and with a large sample throughput can be time consuming.
Lymphoprep™ Tube is a sterile tube, in which the Lymphoprep™ is contained below a plastic filter disc. This allows the diluted blood sample to be poured directly into the tube, the disc preventing any mixing with the Lymphoprep™. The blood may be diluted with saline before pouring or whole blood may be mixed into an equal volume of saline already in the tube.
During centrifugation the erythrocytes (and PMNs) rapidly sediment through the filter disc and the Lymphoprep™ to form the usual large pellet. The latter displaces the Lymphoprep™ upwards, so that the PBMCs band at the interface with the plasma above the disc. The PBMCs may be harvested as usual with a pipette, or the entire liquid above the disc may simply be decanted without any risk of contamination from the erythrocytes and PMNs trapped below the disc.
Lymphoprep™ can be used with either whole (diluted) blood or with a leukocyte-rich plasma (LRP) or buffy coat fraction. With an LRP, Lymphoprep™ permits the recovery of both a PBMC and a PMN fraction. The LymphoprepTM Tube can only be used with whole blood.