Zeiss Opton Refractometer

Description (Brief):

This refractometer was used in Stanley Cohen’s lab at Stanford University in his research on recombinant DNA. 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.

Description (Brief)

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.

Description (Brief)

For more information on the Cohen/Boyer experiments with recombinant DNA see object 1987.0757.01

Description (Brief)

Sources:

Description (Brief)

“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/

Description (Brief)

“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

Description (Brief)

“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.

Description (Brief)

“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.

Description (Brief)

Accession File

Date Made: 1946-1953

User: Cohen, Stanley N.Maker: Zeiss

Location: Currently not on view

Place Made: GermanyAssociated Place: United States: California, Stanford, Stanford

See more items in: Medicine and Science: Medicine, Biotechnology and Genetics, Science & Mathematics

Exhibition:

Exhibition Location:

Credit Line: Stanley N. Cohen, MD and Stanford University Medical Center

Data Source: National Museum of American History

Id Number: 1987.0757.28Catalog Number: 1987.0757.28Accession Number: 1987.0757Serial 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 inoverall: 12 in x 14 in x 6 in; 30.48 cm x 35.56 cm x 15.24 cm

Guid: http://n2t.net/ark:/65665/ng49ca746a9-b426-704b-e053-15f76fa0b4fa

Record Id: nmah_1131224

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