User:Talkingtree

Biopanning is an affinity selection technique which selects for peptides that binds to a given target. This technique is often used for the selection of antibodies.

Biopanning involves 4 major steps for peptide selection. The first step is to have phage display libraries prepared. This involves inserting foreign desired gene segments into 5’ region of genIII bacteriophage vectors such as M17. The result is peptide production which fused to amino terminus of the minor coat protein pIII. The peptides are then expressed on the surface of the bacteriophage.

Next step is the capturing step. It involves conjugating the phage library to the desired target. This procedure is termed panning. It utilizes the binding interactions so that only specific peptides presented by bacteriophage are bound to the target. For example, selecting antibody presented by bacteriophage with coated antigen in microtiter plates.

The washing step comes after capturing step to wash away the unbound phages from solid surface. Only the bound phages with strong affinity are kept. The final step involes the elution step where the bound phages are eluted though changing of pH.

The end result is the peptides produced by bacteriophage are specific. The resulting filamentous phages can infect Gram negative bacteria once again to produce phage libraries. The cycle can occur many times resulting with strong affinity binding peptides to the target.