For the world's biological scientists, Monday was G-Day - the announcement of the first draft of the human genetic code.

Today we hand over the gift of the human genome to the public. It is a powerful force for great good or great evil

Dr Mike Stratton, Sanger Centre

Many began their careers believing this achievement was an impossible dream.

But as the UK's top genome scientists emerged blinking from their laboratories into the glare of the first press conference in London, they could proudly announce that the nearly all the code had been cracked.

About 97% of the human genome had now been mapped with 85% of the code written in DNA accurately sequenced and put in its proper order.

Photographers prowled and reporters howled, but though the researchers were shorn of their lab coats they were armoured with news of a changed world.

The big secret

Dr Mike Dexter, Director of the Wellcome Trust, joked about the heavily trailed announcement: "I can now reveal one of the best kept secrets ever."

He said: "Today could well be regarded as one of the most significant days in human history. The Human Genome Project has the capacity to impact on every human on Earth."

"It's better than the invention of the wheel, because technology could make that obsolete - the genome never will be."

The UK's science minister, Lord Sainsbury, agreed: "We now have the possibility of achieving all we ever hoped for from medicine."

All the back-slapping gave the atmosphere of an awards ceremony.

Prize day

The Wellcome Trust was thanked for bankrolling the UK's contribution.

Dr Dexter: "It's better than the invention of the wheel"

The men and women of the Sanger Centre were praised for their work, which was carried out "not for great financial gain or scientific kudos" but for public benefit. The engineers who build the equipment were lauded as the "great unsung heroes".

But it was Dr Mike Stratton, Head of the Cancer Genome Project at the Sanger Centre, the UK's main sequencing centre, who said the big prize, the human genetic blueprint, was being given to the public.

"Today is the day that we hand over the gift of the human genome to the public. It is very fragile and beautiful and a powerful force for great good or evil," he said.

The responsibility for its use was also being handed over to society, said Dr Stratton.

Mission to explain

Dr John Sulston, leader of the UK's contribution to the Human Genome Project, agreed, adding: "I'm confident that if we can explain this well, so that it becomes part of the democratic process, we will have no problems."

Many of the scientists have said that the first draft of the genome is just a beginning and that this "book of life" still needs interpreting.

But also just beginning is the exploration of what the public will and will not find acceptable in research.

The scientific and financial gains are such that funding will not be a problem for scientists. But, bearing in mind the continuing controversy over genetically modified crops, the most significant hurdle they will have to leap may well be public opinion.