Purified Cell Subsets

Examples of cell subsets commonly isolated are:

• T cells (CD3, CD4, CD8, Pan T Cells)
• NK cells
• Tregs
• CD34+ stem cells
• Plasma B cells
• Monocytes
• Dendritic cells
• Neutrophils
• Other cell isolations available upon request

Positive selection

Cells of interest are labeled using antibody binding properties. Antibodies bound to magnetic beads are placed in the sample, allowing them to bind to surface proteins on the cells of interest. A magnetic field is then applied isolating the bound cells of interest. This results in a highly purified cell subset.

Negative selection 

Unlike positive selection, the cells of interest are left unbound in this technique, i.e. "untouched". Various antibodies bound to magnetic beads are placed in the sample, allowing them to bind to the surface proteins of all present cell populations, except the cells of interest. A magnetic field is then applied, removing the labeled, unwanted cells, resulting in an "untouched" highly purified cell subset.

Positive selection targets a single type of cell and therefore results in a highly purified homogeneous population, however these cells are bound to antibodies that could interfere with cellular signaling.

Negative selection results in unbound cells of interest that have no interference in cellular signaling, but the resulting cells may be less “purified” or less homogeneous compared to positive selection, as multiple cell types have to be accurately targeted in order to remove the cells of interest.