Scientists have created the first man-made synthetic DNA structure -- one of the three key steps towards the formation of artificial life.

The researchers at the J. Craig Venter Institute in Rockville created the artificial genome code -- the chemical blueprint of life -- by synthesising and assembling 582,970 base pair genome of bacterium Mycoplasma genitalium JCVI-1.0.

In the next step, which is ongoing at the JCVI, the researchers would attempt to create a living bacterial cell-based entirely on the synthetically made genome.

"This extraordinary accomplishment is a technological marvel that was only made possible because of the unique and accomplished JCVI team," according to institute's founder Dr J Craig Venter.

But, he claimed that there are a number of serious constraints 'on that happening' and 'we are working diligently to get rid of them.'

"If we had succeeded it would be part of this paper. As soon as we have it, I doubt that we would be able to keep it a secret. Nor would we want to. It is a matter of time," Dr Venter told The Daily Telegraph.

The researchers made DNA fragments in the laboratory into larger pieces using new methods for the assembly and reproduction of the segments to achieve this 'very exciting' milestone.

In fact, after several years of work perfecting chemical assembly, the team found they could harness the process that cells use to repair damage to their chromosomes to complete the job.

The building blocks of DNA -- adenine (A), guanine (G), cytosine (C) and thiamine (T) -- are not easy chemicals to artificially synthesise into chromosomes.

As the strands of DNA get longer they get increasingly brittle, making them more difficult to work with. So, building a synthetic version of the genome of M genitalium genome that has over 580,000 base pairs presented a formidable challenge.

"We have shown that building large genomes is now feasible and scalable so that important applications such as biofuels can be developed. However, such work would use other kinds of bacteria," one of the researchers, Ham Smith, said.