Various pathways to bioconjugates based on thiol chemistry are discussed. Thiol-halogeno, thiol-parafluoro, thiol-ene, thiol-yne, thiol-vinylsulfone and thiol-vinyl sulfone, thiol-maleimide, thiol-bisulfone, and thiol-pyridyl disulfide are well-established synthetic routes discovered in recent years as tools to marry polymers with biomolecules such as carbohydrates, proteins, peptide, DNA, antibodies, or other building blocks from nature.