NOVEL MONOCLONAL ANTIBODIES DIRECTED AGAINST L-THYROXINE AND DIAGNOSTIC USES THEREOF

The present invention provides a novel monoclonal antibody specifically binding to L-Thyroxine (T4) and compositions and kits comprising such antibodies. Furthermore, provided are polynucleotides encoding such monoclonal antibodies, host cells expressing said antibodies, methods of producing such antibodies and diagnostic methods using such monoclonal antibodies. The monoclonal antibody of the invention comprises a heavy chain variable domain (VH) comprising V or A in position 33; Y in position 50; W in position 52; I in position 98, G, A or V in position 99; Y in position 100; and I in position 100b; and a light chain variable domain (VL) comprising amino acids H or Y in position 28; N or K in position 29; W in position 32; G or A in position 91; Y, W or F in position 92; S or T in position 93; Y or F in position 95b; N, S, T or Q in position 95c; and H in position 96, wherein the positions of the amino acids in the VH and the VL are indicated according to the Kabat numbering scheme, respectively.