Merck: SILu™MAb

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.

SILu™MAb K1 & K4 

Stable-Isotope Labeled Universal Monoclonal Antibody (SILu™MAb) K1 and K4 are the two new internal standards in the SILu™MAb collection. These standards serve as a reference point in mass spectrometry analysis; by comparing the similar peaks of SILu™MAb and a sample, the concentration of a target protein in the sample can be determined. SILu™MAb K1 and K4 are highly purified IgG1 and IgG4 antibodies, respectively, that possess kappa peptide chains. These peptides create a stronger resemblance between SILu™MAb and drugs in the pharmaceutical industry.

SILu™MAb Mouse

SILu™MAb Mouse is a recombinant, stable isotope-labeled, mouse monoclonal antibody which incorporates [13C6, 15N4]-Arginine and [13C6, 15N2]-Lysine. Expressed in CHO cells, SILu™MAb Mouse is designed to be used as a universal internal standard for bioanalysis of monoclonal murine antibodies in animal pharmacokinetics (PK) studies.

SILu™MAb Mouse is an IgG1 antibody with a kappa light chain. Because of overlap with common sequences in the Fc region with candidate murine antibodies, SILu™MAb Mouse provides universal utility, and thus, eliminates the need to produce candidate-specific internal standards.


Application Note for SILu™MAb K1

A Universal Dual Peptide Assay for Antibody-Based Drug Candidates in Animal PK Studies Using a Full-Length Stable Isotope Labeled Internal Standard

For more information, visit sigma-aldrich.com/silumab