Method for the synthesis of a bifunctional complex

A split-and-mix method for generating a library of bifunctional complexes comprising a display molecule part and a coding part, which method comprises the steps of:

• providing, separate compartments, nascent bifunctional complexes, each comprising a chemical reaction site and a priming site for enzymatic addition of an oligonucleotide tag;
• performing a round of reaction in each compartment comprising, in any order, a reaction between the chemical reaction site and one or more reactants to provide a new chemical reaction site, and an addition of one or more respective oligonucleotide tags identifying the one or more reactants at the priming site using one or more enzymes to provide a new priming site;
• pooling together the content of two or more compartments and subsequently splitting the pooled contents into an array of compartments for a new round of reaction;
• performing the new round of reaction in each compartment comprising, in any order, a reaction between the new chemical reaction site and one or more reactants to provide a reactant specific reaction product, and an addition of one or more respective oligonucleotide tags identifying the one or more reactants at the new priming site using one or more enzymes,
• obtaining the library of bifunctional complexes in which each member of the library comprises a display molecule part comprising a reactant specific reaction product and a coding part comprising respective oligonucleotide tags which code for the identity of each of the reactants that have participated in the formation of the reactant specific reaction product.