Bi-functional complexes and methods for making and using such complexes

A method for the synthesis of a bi-functional complex comprising a molecule part and an identifier oligonucleotide part identifying the molecule part, the identifier oligonucleotide part comprising a first identifier oligonucleotide tag and a second identifier oligonucleotide tag which identify a first reactive compound building block and a second reactive compound building block, respectively,

• said method comprising the steps of
• i) linking the first identifier oligonucleotide tag comprising a chemical reaction site to a solid support,
• ii) reacting in an organic solvent the first reactive compound building block with the chemical reaction site,
• iii) reacting in an organic solvent the second reactive compound building block with the chemical reaction site and/or with the first reactive compound building block, and
• iv) enzymatically ligating in an aqueous medium the first identifier oligonucleotide tag and the second identifier oligonucleotide tag,
• wherein said reactive compound building block reactions generate the molecule part of the bi-functional complex, and wherein said enzymatic ligation of said oligonucleotide tags generates the identifier oligonucleotide part of the bi-functional complex, and wherein the bifunctional complex is linked to the solid support.