Bioconjugation is a burgeoning field of research. Novel methods for the mild and site-specific derivatization of proteins, DNA, RNA, and carbohydrates have been developed for applications such as ligand discovery, disease diagnosis, and high-throughput screening. These powerful methods owe their existence to the discovery of chemoselective reactions that enable bioconjugation under physiological conditions-a tremendous achievement of modern organic chemistry. Here, we review recent advances in bioconjugation chemistry. Additionally, we discuss the stability of bioconjugation linkages-an important but often overlooked aspect of the field. We anticipate that this information will help investigators choose optimal linkages for their applications. Moreover, we hope that the noted limitations of existing bioconjugation methods will provide inspiration to modern organic chemists.