Overcoming antibody expression and screening limitations by smart design: Applications to PSA immunoassay development

► A method for improved antibody fragment expression in Escherichia coli is proposed. ► Reformatting of scFvs into scAbs significantly enhances expression and screening performance. ► High precision kinetic analysis was performed using a 'customised' Biacore applications wizard. ► The best clone selected was incorporated into a sandwich-based immunoassay for PSA. ► Initial antibody format design significantly effects potential clone selection quality.