The selection of buffers should take into account the stability of the target, the binding microenvironment, and minimal non-specific binding in the actual application scenario. Unrelated proteins, non-ionic detergents, and physiological salt concentrations is conducive to reducing the background. There are also other conditions, such as some targets may require the addition of bivalent cations or other cofactors to the buffer, protein cofactors can be co-fixed with the target, can be added to the sorting buffer, and even can be used as a means of capturing the target.

Common selection pressure considerations include concentration of target molecules, binding time, washing intensity, etc. Other techniques for increasing selection pressure include the use of denaturants (such as acids, urea, and guanidine), organic solvents, increasing temperature, or increasing the concentration of competing ligands or targets in the washing buffer.
Among them, the first round of screening is important. The first round of screening is to capture as many positive clones as possible from the constructed library while removing non-specific clones. Porous-coated targets or a large number of soluble targets should be used to ensure that a large number of bound phages are captured to maintain the diversity of the library. In subsequent rounds of screening, the selection pressure should be increased with the increase of enrichment, multiple washing, and increasing the washing time, clones with high affinity can be screened.

Antigen tags and carrier materials the screening process is to screen for all substances on the antigen conjugates, such as tags, fusion proteins, and supporting substrates. Negative screening of non-targets can limit the enrichment of antibodies other than the target antigen.
Whole cells, liposomes, nano-phospholipid discs, and VLPs can be negatively screened using simulated transfected cells or untransfected cells when screening transfected cell lines.
Removal of complex antigen mixtures Strict negative screening can be performed for unknown or complex target molecules, such as whole cells or impure proteins.
The strategy of antibodies against specific sites of antigens, one is to eluate the antibody that can compete with the ligand by adding a high concentration of ligands, and the other is to block the antibody.

*Antibody discovery has become increasingly important in modern medicine. Different antibody discovery approaches exist, but phage display technology is used more in medical science. Since 1990, different antibody formats have been used to construct phage libraries, including VHs, VHHs, scFvs, diabodies, and Fab antibodies.
*Phage peptide libraries allow the rapid determination of the sequence of protein epitopes and have become a powerful tool for investigating the interaction between epitopes and antigen receptors
*Antibody fragments are fused to the G3P of the M13 phage, and by cloning large numbers of genes encoding an antibody fragment, large phage display antibody libraries can be generated from which many diverse antibodies can be selected.
*The T7 phage display system has many advantages, including simplicity, high safety, stability, easy storage, and transportation, so the system is used in preventive and therapeutic vaccines.
*The T7 phage display system can detect various antigens, such as surface antigens of pathogenic microorganisms and cancer antigens.