The REA Control (I) antibody clone REA293 is a universal isotype control that can be used with all recombinant engineered antibodies (REAfinity™ Antibodies) that recognize intracellular antigens. REAfinity Antibodies have been engineered for their high specificity and contain human IgG1 parts for constant regions. Unspecific interactions of the fluorochrome can be controlled for with conjugated versions of clone REA293. For intracellular stainings however the isotype control staining should be combined with other negative controls (e.g. staining of unstimulated cells).