Flow Cytometry is a powerful method to identify, characterize and quantify normal and abnormal plasma cells in human whole blood, bone marrow and apheresis products. The phenotype of abnormal plasma cells (PCs) is not defined by a single specific antigen expression pattern but by any deviation from the well-defined antigen expression pattern of the normal PC phenotype. Discrimination of small populations (e.g. 50 events) of these abnormal cells from a background of hundreds of thousands to millions of normal leukocytes including normal PCs can be challenging as expression of PC gating markers can be modulated (e.g. therapeutic intervention, multiple myolema cells, Table 1). Furthermore, PC characterization markers are commonly expressed by other normal leukocyte populations which require diligent verification of the target cells’ identity.
The DuraClone RE PC Tube contains the gating markers CD138 and CD38 as well as antibodies frequently used for characterization, i.e. CD19, CD27, CD45, CD56, CD81 and CD200. Furthermore, inclusion of CD45 allows for quantifying plasma cells relative to the leukocyte event count. The antibody dosing accommodates staining of 100- 200μL suspension enriched to a total leukocyte count of 3-5 millions.