Suitable for analysis of LDL receptor function in patients with familial hypercholesterolemia. The antibody recognizes an epitope in the region of repeat #1 of the ligand binding region. Addition of 15 nM antibody results in inhibition of half-maximal LDL-binding (Beisiegel et al. 1981). In human normal fibroblasts the antibody detects the 160 kD polypeptide (pI 4.3) and also in bovine adrenal gland (160 kD; pI 4.6) of LDL receptors (Beisiegel et al. 1982). Beisiegelt, U., Schneider, W. J., Brown, M. S. & Goldstein, J. L. Immunoblot Analysis of Low Density Lipoprotein Receptors in Fibroblasts from Subjects with Familial Hypercholesterolemia. J. Biol. Chem. 257, 13150–13156 (1982).Beisiegel, U., Schneider, W. J., Goldstein, J. L., Anderson, R. G. & Brown, M. S. Monoclonal antibodies to the low density lipoprotein receptor as probes for study of receptor-mediated endocytosis and the genetics of familial hypercholesterolemia. J. Biol. Chem. 256, 11923–31 (1981).