Spectroscopic determination of chelator content in antibody-chelator conjugates - UV/Vis, fluorescence, and MALDI-TOF MS studies

The increasing use of monoclonal antibody-bifunctional chelator conjugates in clinical practice has created the need for quality control procedures pr oviding relatively simple and reliable determination of the chelator-to-pro tein (C/P) ratio. Spectroscopic methods offer a valuable alternative to the use of radioactive isotopes for this purpose. This article discusses the a pplication of UV/Vis spectrophotometry, fluorescence spectroscopy, and matr ix-assisted laser desorption ionization time-of-flight mass spectrometry (M ALDI-TOF MS) for the quality control of MAb-chelator conjugates.