Not sure which SILu™MAb is right for you? Download our new Antibody Isoforms poster to see the different disulfide bonds, glycans, and structures associated with IgG isoforms. Our Stable Isotope-Labeled Universal Monoclonal Antibody (SILu™MAb) is a critical tool for the assessment of pharmacokinetic properties of biotherapeutics. SILu™MAb is a highly purified, stable isotope-labeled IgG monoclonal antibody (expressed in a proprietary Sigma-Aldrich CHO cell line) that utilizes universal heavy-labeled tryptic peptides as internal standards for the quantitation of monoclonal antibodies and Fc-fusion therapeutics. As a full-length protein standard with universal utility, it eliminates the need for the production of candidate-specific internal standards and reduces errors associated with fractionation, enrichment, and proteolysis. SILu™MAb also offers a variety of advantages over traditional ELISA-based methods, such as superior specificity, sensitivity, and reduced matrix effects.