14 February 2008
Heterophilic antibodies, which are endogenous antibodies found in human serum/plasma, may bind to the animal antibodies used in immunoassays and produce erroneous results. An example is the immunoglobulins that bind the Galα1-3Gal epitope and constitute ca. 1% of total serum IgG. These antibodies are responsible for the hyperacute rejection of xenografts and are thought to be synthesized in response to the Galα1-3Gal epitope produced by the human gut flora (Galili, 2005).
In a recent study it was shown that these antibodies interfered in an assay to measure galactose deficient anti-Gal IgG in the sera of patients with liver fibrosis and cirrhosis caused by infection by hepatitis C virus. This interference could be overcome by the inclusion of human serum albumin (HSA) attached to alpha-Gal obtained from Dextra Laboratories in the ELISA assay (Mehta et al. 2008).
We offer 3 alpha-Gal HSA neoglycoproteins that can be used in this application:
•NGP2330 Galα1-3Galβ1-4Glc-HSA 3-atom spacer
•NGP2334 Galα1-3Galβ1-4GlcNAc-HSA 3-atom spacer
•NGP3334 Galα1-3Galβ1-4GlcNAc-HSA 14-atom spacer
References
Gallili, U. (2005). The alpha-Gal epitope and the anti-Gal antibody in xenotransplantation and in cancer immunotherapy. Immunol. Cell Biol. 83:674-686
Mehta, S.A., Long, R.E., Comunale, M.A., Wang, M., Rodemich, L., Krakover, J., Philip, R., Marrero, J.A., Dwek, R.A. and Block, T.M. (2008). Increased Levels of Galactose-Deficient Anti-Gal Immunoglobulin G in the Sera of Hepatitis C Virus-Infected Individuals with Fibrosis and Cirrhosis. J. Virol. 82(3):1259-1270
30 January 2008
We have introduced new linker arm chemistry for our blood group A and B neoglycoproteins. This has been necessary because there were problems of poor manufacturing yields using these trisaccharides with our standard 3 and 14 atom linker arms and reports of lower substrate affinities, for example antibody binding, with the 20 atom linker. As a solution, we have developed a new proprietary polar 6 atom linker that we think will overcome our problems and will meet users’ needs. The new products will carry the catalogue numbers:
•NGP 6305 Blood Group A-BSA (6-atom spacer)
•NGP 6323 Blood Group B-BSA (6-atom spacer)