How do you build the nucleotides to form synthetic DNA?

Answer

Hi Len,

Making synthetic DNA is something that has been happening more and more often in the last decade. Just as the cost of sequencing (reading) DNA has been greatly reduced, so has the cost of assembling synthetic DNA. There are companies that focus very specifically on this (eg IDT DNA, which are located in Haasrode near Leuven). You can order DNA sequences from them for a few tens of euro cents per base (the longer the sequence, the higher the cost per nucleotide).

How is this happening now? First, indeed, nucleotides have to be made from simple building blocks. Care must be taken in this step that no mistakes are made, and it is very important to obtain the correct nucleotides very pure. The second step is to assemble these nucleotides into oligonucleotides (chains of nucleotides joined together). This is done by carrying out a series of chemical reactions for each nucleotide, whereby an extra nucleotide is attached to the growing chain of nucleotides. This step also has to be done very efficiently, otherwise it can happen that a nucleotide is not attached properly, and then you have a wrong DNA strand. In a final step, the strand must also be purified.

In other words, the complete synthesis of a synthetic DNA strand is anything but easy and doing it all yourself is impossible I think.

Regards,
Benjamin