Heritage Auction is about to start accepting bids on a rare item indeed: the 1962 Nobel Prize in Physiology or Medicine awarded to Francis Crick, one of the three men who deciphered the famous double helix of DNA back in 1953.

Crick died in 2004 and now his 36-year-old granddaughter says it isn't doing any good "tucked away" in the family's safe-deposit box. "We really were interested in finding someone who could look after it, and possibly put it on display so it could inspire the next generation of scientists," Kindra Crick told LiveScience.

Heritage Auctions has valued the medal and Crick's accompanying diploma at $500,000 – what they call an "educated guestimate." Some of Heritage's in-house estimates placed the value at as high as $5 million. There's very little basis in history to go on for these estimations: Heritage told ABC News that they know of only one other Nobel Prize that has ever been sold.

Crick's granddaughter said some of the proceeds will be donated to research institutions, including the Salk Institute in the U.S. and the forthcoming Francis Crick Institute, which is scheduled to open in London in 2015 as an interdisciplinary medical research lab studying diseases, cancer, heart disease and other illnesses. The institute is being funded by a consortium of six scientific and academic organizations and is expected to eventually employ 1,250 scientists.

Kindra Crick says she has never actually seen her grandfather's Nobel Prize, as he "was not the type of personality to show off." She hopes whoever buys the medal will put it on public display somewhere.

Crick's Nobel Prize goes up for auction this April.