What’s the difference between positive and negative selection of cells?

Positive selection involves targeting a desired cell population with an antibody specific to a cell surface marker (e.g., CD3, CD8, CD19, etc.) and then linking to a magnetic particle. The sample incubates in a magnetic field and the labeled, linked cells are retained for downstream analysis. Negative selection is when several cell types are removed through buy using and antibody cocktail and magnetic beads, leaving the cell type of interest untouched. Negative selection offers true untouched cell samples, which is our recommended mode of isolation where applicable.