A letter sent by Francis Crick to his son that outlines his discovery of the structure and function of DNA will be offered at Christie's on April 10.

'We think we have found the basic copying mechanism by which life comes from life'

The 1953 letter is expected to sell for $1m-2m, as an important memento from one of the most significant scientific revelations in history. It is written in plain English to Crick's 12-year-old son, who was at boarding school at the time.

Crick's co-discovery with James Watson of DNA's shape and the code behind it today forms our understanding of how life is made and replicated. The famous double helical structure of DNA had long been supposed, but it was Crick and Watson who first proved it with their model.

The letter reads in part: "Jim Watson and I have probably made a most important discovery. We have built a model for the structure of de-oxy-ribose-nucleic-acid (read it carefully) called D.N.A. You may remember that the genes of the chromosomes - which carry the hereditary factors - are made up of protein and D.N.A."

'Our structure is very beautiful...'

Not only does Crick's seven-page missive detail the discovery, but it also reveals the human side to this important event. A charming piece, Crick signs off "Lots of love, Daddy."

The sale will follow the 60th anniversary of the announcement of the discovery, which occurred in February/March 1953. Heritage Auctions' will also sell the Nobel Prize that Crick was awarded for his discovery in 1962, which is offered with a $500,000+ estimate.

PFC Auctions is currently offering a series of correspondence between Albert Einstein and socialist philosopher Corliss Lamont, which reveals Einstein's involvement in the politics surrounding the cold war.