Regulation of polymerase using cofactor oxidation states

An oligonucleotide synthesizer configured for polynucleotide synthesis using a template independent polymerase comprising:

• an array covered with a plurality of initiators attached thereto each having a 3′ terminal nucleotide;
• a solid metal source;
• a metal cofactor oxidation state control mechanism that oxidizes the solid metal source on the array to release a metal cofactor in a +2 oxidation state;
• control circuitry communicatively coupled to the metal cofactor oxidation state control mechanism and configured to selectively activate the metal cofactor oxidation state control mechanism on the array;
• and
• a reaction reagent solution in contact with the array and comprising the template independent polymerase, a selected nucleotide, and a chelator.

An oligonucleotide synthesizer configured for polynucleotide synthesis using a template independent polymerase comprising:

• a microelectrode array including spatially addressable electrodes, the microelectrode array covered with a plurality of initiators attached thereto each having a 3′ terminal nucleotide;
• a solid metal source;
• control circuitry communicatively coupled to the microelectrode array and configured to oxidize the solid metal source to release a metal cofactor in a +2 oxidation state;
• and
• a reaction reagent solution in contact with the microelectrode array and comprising the template independent polymerase, a selected nucleotide, and a scavenger that is a redox reagent which oxidizes or reduces the metal cofactor to an oxidation state other than the +2 oxidation state or a chelator.