Method for synthesizing nucleic acids, in particular long nucleic acids, use of said method and kit for implementing said method

The invention relates to a method for synthesising long nucleic acids, including at least one cycle of elongating initial fragments of nucleic acids, including a) a phase comprising the enzymatic addition of nucleotides to said fragments, b) a phase comprising the purification of the fragments having a correct sequence, c) an optional phase of enzymatic amplification, each cycle being performed in a reaction medium which is compatible with enzymatic addition and amplification, such as an aqueous medium, the synthesis method also comprising, at the end of all the elongation cycles, a last step of final amplification. The invention also relates to the use of the method for the production of genes, or sequences of synthetic nucleic acids, DNA or RNA. The invention further relates to a kit for implementing said method.