The development of the phage display technique has brought practicality and speed when selecting high-affinity molecules. It is used to obtain single-chain variable fragments (scFvs) and has revolutionized several branches of research and industry. These are developed from gene libraries that differ in their construction strategies, which causes a diversity of sequences, specificity and binding strength of the projected molecule to its antigen. In this review, we present the recent studies that demonstrate methods and approaches using immune, naïve, synthetic and semisynthetic libraries to construct and select scFvs. Subsequently, the characteristics of these libraries, the functionality of the scFvs and the cost-benefits of production will be discussed. In addition, we highlight the methodological trends and challenges to be overcome in order to optimize the production and application of these antibody fragments.
Keywords: Gene libraries; biotechnological applications; phage display; sequence diversity; target affinity.