Patent ID: 7279287

Claim:
A method for determining the total amount of an anti-HER2 antibody in a fluid sample in the presence of an interfering substance HER2 extracelluar domain (ECD), comprising: (a) providing a first antibody recognizing said anti-HER2 antibody present in a free form and a second antibody recognizing said interfering substance when bound to said anti-HER2 antibody wherein said first and second antibodies comprising different label respectively; (b) contacting said first antibody and said second antibody with said fluid sample, whereby said first antibody binds said anti-HER2 antibody and said second antibody binds said interfering substance bound to said anti-HER2 antibody; and (c) determining the total amount of the anti-HER2 antibody present in free form and bound to said interfering substance.