Some of the latest, most promising therapeutic developments in the biologics industry use antibody fragments — either separate functional subunits of antibodies or recombinant molecules that are composed of immunoglobulin domains. The most popular fragments are antigen-binding fragments (Fabs), variable single-chain fragments (scFvs), diabodies, and nanobodies. Such molecules raise several advantages over their parent molecules for upstream production but pose several challenges for downstream purification. To facilitate antibody-fragment capture, Tosoh Bioscience has developed Toyopearl AF-rProtein L-650F resin. Its ligand uses…