Barbara McClintock (1902-1992) used this microscope in the 1940s and 1950s for research on transposing genetic elements or “jumping genes” in maize. In this process, segments of DNA jump from one location on a chromosome to another. When Dr. McClintock published her results, she met with skepticism from many fellow geneticists. However, in 1983 she was awarded the Nobel Prize for her work. It was eventually determined that these elements are found in virtually all living organisms.
This instrument, made by Bausch & Lomb Optical Co., is fitted with a circular mechanical revolving stage designed specifically for photomicrography. Dr. McClintock gave the microscope, and its set of apochromatic lenses, to Dr. Joseph C. Gall of the Carnegie Institution in Washington, D.C. in the summer of 1977. She told him she no longer needed it and wanted it to be in safe hands. In 1993 the Carnegie Institution donated the instrument to the Smithsonian Institution.
Currently not on view
Object Name
date made
ca 1940
Bausch & Lomb
Physical Description
metal (overall material)
average spatial: 31.1 cm x 17.7 cm x 19 cm; 12 1/4 in x 6 15/16 in x 7 1/2 in
place made
United States: New York, Rochester
ID Number
catalog number
accession number
Science & Scientific Instruments
Artifact Walls exhibit
Science & Mathematics
See more items in
Medicine and Science: Biological Sciences
Artifact Walls exhibit
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Carnegie Institution of Washington
Additional Media

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.