Object Details
- Description (Brief)
- Refractometers measure how light changes velocity as it passes through a substance. This change is known as the refractive index and it is dependent on the composition of the substance being measured. In the Cohen lab, this refractometer was one of several techniques used to provide evidence that he and his research team had created a recombinant DNA molecule containing DNA from both a bacterium and a frog.
- To conduct the analysis, Cohen separated out the molecule he assumed to be recombinant DNA and measured its refractive index. The index for the molecule fell between the known values for frog DNA and bacterial DNA, suggesting that the unknown DNA molecule was a mixture of the two.
- For more information on the Cohen/Boyer experiments with recombinant DNA see object 1987.0757.01
- Sources:
- “Section 9.4.2: Buoyant Density Centrifugation.” Smith, H., ed. The Molecular Biology of Plant Cells. Berkeley: University of California Press, 1977. http://ark.cdlib.org/ark:/13030/ft796nb4n2/
- “Louisiana State University Macromolecular Studies Group How-To Guide: ABBE Zeiss Refractometer.” Pitot, Cécile. Accessed December 2012. http://macro.lsu.edu/howto/Abbe_refractometer.pdf
- “Construction of Biologically Functional Bacterial Plasmids In Vitro.” Cohen, Stanley N., Annie C.Y. Chang, Herbert W. Boyer, Robert B. Helling. Proceedings of the National Academy of the Sciences. Vol. 70, No. 11. pp.3240–3244. November 1973.
- “Replication and Transcription of Eukaryotic DNA in Escherichia coli.” Morrow, John F., Stanley N. Cohen, Annie C.Y. Chang, Herbert W. Boyer, Howard M. Goodman, Robert B. Helling. Proceedings of the National Academy of the Sciences. Vol. 71, No. 5. pp.1743–1747. May 1974.
- Accession File
- Description
- Refractometer with a “ZEISS / OPTON / Nr 128464 / Germany” inscription used in Stanley Cohen’s laboratory at Stanford University, for research on recombinant DNA. After World War II, the Zeiss firm was split into two parts: VEB Zeiss Jena in the east, and the Opton Optische Werke Oberkochen in the west.
- Location
- Currently not on view
- date made
- 1946-1953
- user
- Cohen, Stanley N.
- maker
- Zeiss
- place made
- Germany
- associated place
- United States: California, Stanford, Stanford
- See more items in
- Medicine and Science: Medicine
- Biotechnology and Genetics
- Science & Mathematics
- Credit Line
- Stanley N. Cohen, MD and Stanford University Medical Center
- Data Source
- National Museum of American History
- ID Number
- 1987.0757.28
- catalog number
- 1987.0757.28
- accession number
- 1987.0757
- serial number
- 128646
- Object Name
- refractometer
- Physical Description
- metal (overall material)
- glass (overall material)
- plastic (overall material)
- Measurements
- average spatial: 21.7 cm x 33 cm x 16.7 cm; 8 17/32 in x 13 in x 6 9/16 in
- overall: 12 in x 14 in x 6 in; 30.48 cm x 35.56 cm x 15.24 cm
- Record ID
- nmah_1131224