A Nobel Prize awarded to chemist Hans Krebs is up for auction at Nate D Sanders.
Krebs received the medal in 1953, in recognition of his discovery of the citric acid cycle - which explains the way cells convert food into energy.
Krebs was awarded the Nobel Prize in 1953
The finding was published in scientific journal Nature in 1937 and was a major breakthrough in the study of biochemistry.
The medal is valued in excess of $550,000 ahead of the April 28 auction.
It last sold for ?�275,000 (then $430,476) at Sotheby's London last year.
Nobel Prizes have been sold in increasing numbers in recent years. The record is $4.7m, set for the one awarded to DNA scientist James Watson at Christie's in 2014.
An anti-Semitic letter written by US president William Taft (1909-1913) is expected to make more than $15,000.
The text dates to 1916, three years after Taft's presidency ended, and concerns Woodrow Wilson's election of Louis Brandeis to the Supreme Court.
It's addressed to close friend Gus Kraiger and includes numerous barbed references to Brandeis' ethnicity.
Brandeis was the first Jewish member of the Supreme Court and a long-time political opponent of Taft. Taft publicly (and bitterly) opposed his election.
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