The BBC's James Wilkinson explains the process of making a brand new life form

They are proposing to take the genes from the simplest living organisms and use them to make completely new individuals which may then reproduce.

Before they begin the project, scientists at the Institute for Genomic Research in Maryland plan to ask religious and ethical experts at the University of Pennsylvania to consider the moral implications of such a venture.

Genes would have to strung into a "helix"

The kind of life form they are proposing to make is a bacterium, possibly from as little as 300 genes, and scientists say that within a decade they should be able to make one from scratch.

First they need to string the genes into a double helix and then place it into a cell wall. If they are successful, their creation might start to reproduce and take on a life of its own.

Cells could be injected with synthetic genes

Commenting on the dramatic announcement, made at the American Association for the Advancement of Science conference in California, Professor Steve Jones of University College London, said: "If one can make a bacterium from a genetic blueprint from chemicals you lift off the shelf - and I emphasise the word 'if' - and that bacterium then divides and copies itself, it is hard to deny that it's alive."

Risk of the unknown

John Durant, Professor for the Public Understanding of Science at Imperial College in London, highlighted the benefits of such technology.

Professor Durant of Imperial College London: "With artificial microbes, we could create new drugs and vaccines"

"One of the main aims of creating artificial bacteria is that they could be given just the properties that people want to produce new drugs, new vaccines, even new materials for use in industry," he said.

The main disadvantage of creating synthetic life forms, he said, was "the risk of the unforeseen".

He told the BBC: "What the Americans are proposing to do is to put together genes of their choosing into a cell, but they won't be able to predict in advance every single property that that cell has."