Abstract
The selection of aptamers represents a promising route in the development of high affinity ligands. In these processes the formation of by-products is a common problem during the PCR-based amplification of complex oligonucleotide libraries. One approach to overcome this drawback is to separate each template oligonucleotide into an individual reaction compartment provided by a droplet. This method, termed emulsion PCR (ePCR), has already emerged to a standard method in sample preparation for 2nd generation sequencing. In this work, we compare different literature protocols that have been developed to generate stable emulsions for ePCR. We investigate different emulsification methods and evaluate the importance of the initial template concentration. We demonstrate that emulsion stability is of utmost importance for the successful inhibition of by-product formation and give an optimized protocol for generation of an emulsified PCR.