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The Francis Crick Papers

Title:
Letter from Francis Crick to Marshall W. Nirenberg pdf (94,320 Bytes) transcript of pdf
Letter from Francis Crick to Marshall W. Nirenberg
Number of Image Pages:
1 (94,320 Bytes)
Date:
1962-01-29 (January 29, 1962)
Creator:
Crick, Francis
Recipient:
Nirenberg, Marshall W.
Source:
Original Repository: Wellcome Library for the History and Understanding of Medicine. Francis Harry Compton Crick Papers
URL: http://archives.wellcome.ac.uk/Exit
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Rights:
Reproduced with permission of the Wellcome Library for the History and Understanding of Medicine.
URL: http://library.wellcome.ac.uk/Exit
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Exhibit Category:
Deciphering the Genetic Code, 1958-1966
Relation:
Metadata Record Letter from Francis Crick to Marshall W. Nirenberg (January 29, 1962) (in The Marshall W. Nirenberg Papers) pdf (67,031 Bytes) transcript of pdf
/ps/access/JJBBGN.pdf
Box Number: 10
Folder Number: PP/CRI/D/1/1/14
Unique Identifier:
SCBBSP
Document Type:
Letters (correspondence)
Language:
English
Format:
application/pdf
image/tif
Physical Condition:
Good
Series: Correspondence
SubSeries: Alphabetical Correspondence
SubSubSeries: Correspondence 1
Folder: Correspondence N
Transcript:
29th January, 1962.
Dear Dr. Nirenberg,
Thank you for your revised paper. We, too, thought we had evidence for degeneracy, as in our hands both poly (U,C) and Poly (U,A) incorporate leucine, and the result is not due to an impurity in the isotope. However, the argument obviously depends upon poly U not incorporating leucine, so we retested this. To our surpmise and annoyance we found that our poly U does stimulate the incorporation of some leucine. The mount varies but on one occasion it was as high as 25% of the phenyalalamine incorporated.
NaturalIy we believe that the result with poly U is an artifact, but we have not been able to track it down. Until we have done this we don't feel we can trust the evidence from the other polymers.
As far as we can see the result is not due to impurities in our poly U. Apart from the fact that the polymers have been analysed by Marianne we do not find the incorporation of other amino acids which we should expect if other bases were present in our poly U.
I hope by the time we meet we shall have found the cause of the trouble.
Looking forward to discussing all this with you,
Yours sincerely,
F. H. C. Crick
Metadata Last Modified Date:
2010-01-04
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