Isotype Controls

When you use rare populations or multicolour panels, the background staining levels can create issues. Using isotype controls, which are essentially antibodies against an antigen, which is not in the given sample, are useful.

These controls are optimized for surface staining, and they shouldn’t be used for distinguishing negative and positive cells or gating, because they are not developed specifically for intracellular staining. The best isotope control for the job should match the host species, the fluorophore of the primary antibody and the Ig subclass.