What is the maximum length a DNA oligo can be synthesized?

The real answer lies in the resolution limit of the purification method and on the coupling efficiency of the DNA synthesizer. We can synthesize DNA oligos of 220 bases and obtain sufficient quantities by HPLC purification to perform successful gene construction. However, it should be remembered that the longer the oligo, the greater the chance of accumulated sequence errors.

Coupling efficiency is the factor that mainly affects the length of DNA that can be synthesized. Base composition and synthesis scales will also be contributing factors. For more information regarding coupling efficiency, please refer to the FAQ "What is coupling efficiency?".

Importantly, the probability of premature synthesis interruption increases dramatically for longer oligos, due to poor nucleotide-coupling efficiency. Moreover, the synthesis of special “long oligos” requires more raw material, such as amidites and solutions that need to be used in higher excess.

However, as we are very experienced in producing very long oligos, do not hesitate to discuss your projects with our specialists.