Antibody drug conjugates (ADC) couple therapeutic monoclonal antibodies (mAb) with potent toxins through a linker that is stable within systemic circulation, but cleaves within the target cells. In this report, silyl ether chemistry was used to couple the mAb trastuzumab with the chemotherapeutic, gemcitabine, to demonstrate the use of silyl ethers as a potential linker for ADCs.