Quantitative PCR is a Valuable Tool to Monitor Performance ofDNA-Encoded Chemical Library Selections

摘要

Phage-display libraries and DNA-encoded chemical libraries (DECL) represent useful tools for the isolation of specific binding molecules out of large combinatorial sets of compounds. In both methods, specific binders are recovered at the end of affinity capture procedures, using target proteins of interest immobilized on a solid support. However, while the efficiency of phage-display selections is routinely quantified by counting the phage titer before and after the affinity capture step, no similar quantification procedures have been reported for the characterization of DNA-encoded chemical library selections. In this article, we describe the potential and limitations of quantitative PCR (qPCR) methods for the evaluation of selection efficiency, using a combinatorial chemical library with more than 35 million compounds. In the experimental conditions chosen for the selections, a quantification of DNA input/recovery over five orders of magnitude could be performed, revealing a successful enrichment of abundant binders, which could be confirmed by DNA sequencing. qPCR provides rapid information about the performance of selections, thus facilitating the optimization of experimental conditions.