A review which describes a modified form of the filter-lift assay, designated capture lift, in which phage-expressed soluble Fabs are selectively captured on the nitrocellulose, considerably enhancing the signal of the assay.The nitrocellulose filters are coated with an antibody (Ab) capture reagent, i.e., a polyclonal anti-κ-chain Ab, and the remaining protein-binding sites are blocked prior to performing the plaque lift.The selective binding of phage-expressed Fab, together with the reduced binding of unrelated bacterial proteins, improve the sensitivity of the assay.For the rapid one-step identification of higher-affinity Abs presenting complex Fab libraries, the capture-lift screen can be used by probing the filters with antigen (Ag) at concentrations below the Kd of the Ab-Ag interaction.The increased sensitivity and normalization of the amount of Fab bound on the nitrocellulose in the capture-lift assay increases the utility of filter-lift screening, allowing broader applications in both the discovery and the engineering of phage-expressed Fabs.