Peripheral Blood Mononuclear Cell
A peripheral blood mononuclear cell (PBMC) is a blood cell with a single round nucleus. PBMC that are sometimes referred as PMNC (peripheral mononuclear cell) or MNC (mononuclear cell) includes all mononuclear leukocytes such as Lymphocytes (T-Cells, B-Cells, NK-Cells), Monocytes, Dendritic-Cells and Basophils.
The term PBMC is strongly associated with the enrichment of cells out of whole blood via a density gradient centrifugation. Polymorphonuclear leukocytes (multi-lobed nuclei) such as granulocytes are depleted in that fraction. Granulocytes (neutrophils and eosinophils) can’t be enriched from a PBMC fraction made by a standard density gradient separation*. Basophils differ in their dense and partially can be found in the PBMC fraction. Red blood cells are reduced to a minimum compared to the starting cell count.
* Medium with a density of 1.077 g/ml
Enrichment of PBMC via density centrifugation
Density gradient enriched PBMC are sometimes called buffy coat. In this context, buffy coat describes the layer of enriched leukocytes in the interphase.
First, a synthetic polymer solution with a defined density is overlayed with blood or sample material. This sample preparation is followed by a centrifugation step. At the interphase of both solutions, the cells accumulate with the corresponding density of the polymer solution. Then the interphase, which contains the PBMC, is carefully removed. The enriched mononuclear cells are washed and used for further application.