Optimizing phage elution for biopanning of plastic materials.

Biopanning of phage-displayed peptides is a useful method for peptide probe discovery and has been applied to multiple plastic targets. The most widely used elution method on plastic targets, acidic glycine buffer, is well-established as a general binding disrupter for protein targets, but a comparative study of elution buffers for plastic targets has never been published. Here we demonstrate how elution from plastics with mild surfactant C12E8 or ethanol increases phage yield up to 1000-fold compared to the commonly used acidic elution while also yielding more diverse phage populations. This implies that the classical acidic elution method fails to recover a substantial fraction of plastic binding phage clones. The alternative elution methods described here should therefore be considered when applying biopanning to non-protein targets, where acidic elution is unlikely to disrupt binding through pH-induced conformational changes.