Rare Event Analysis
Dendritic cells (DCs) are rare events in the blood and there are few specific antibodies available to identify them. They are best identified by exclusion of all other lineages and are referred to as Lin-. To achieve this blood cells are labelled with a cocktail of antibodies specific for T, B and NK cells as well as monocytes and granulocytes. Mononuclear cells that are negative for these antibodies are then deemed to be DCs. DCs express high levels of class II HLA molecules so they can be further identified by gating on this and the surface expression of various antigens on the DCs can then be determined.
Immunophenotyping
These cells are also rare events in the blood and so may be identified in a similar way to dendritic cells by excluding unwanted cells from the analysis. So for example by excluding all cells that are CD2, CD19 and CD33 positive this will allow analysis of non committed cells. The addition of antibodies to stem cells (CD133) or specific progenitor phenotypes (VEGF-R) will then allow identification of specific progenitor cells. e.g.immunophenotyping stem cells in Head and Neck Squamous cell carcinoma cell line, CaLH2.