Nobel laureate James Watson is planning to auction his Nobel medal.
It will be the first known time a living recipient has put his medal up for auction.
Professor Watson shared the 1962 Nobel prize with Maurice Wilkins and Francis Crick for their discovery of the structure of DNA. Each was given a gold medal.
The auctioneer says the medal could attract between $2.5m (£1.6m) and $3.5m (£2.2m).
The auction includes papers belonging to Watson, including handwritten notes for his acceptance speech.
Christie's estimates these at between $300,000 (£190,000) and $400,000 (£254,000).
Prof Watson said some of the proceeds would go to the University of Chicago, Clare College at Cambridge University, Cold Spring Harbor Laboratory, Long Island Land Trust and other charities.
The structure of DNA encodes the genetic instructions for developing and the functioning of all living organisms. Watson and Crick unravelled the mystery, using data from experiments gathered by Maurice Wilkins and Rosalind Franklin.
Francis Crick's Nobel medal sold for $2.2m last year. He died in 2004.
