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Lawrence Berkeley Laboratory Life Science Division technical records of Robert K. Mortimer, Undated

Description of Collection


Lawrence Berkeley National Laboratory, Archives and Records Office

1 Cyclotron Rd. MS: 69R0102
Berkeley, California 94720

Papers created by

Lawrence Berkeley Laboratory. Life Sciences Division

Size of collection

6.25 linear feet
5 records boxes

Short description of collection

These records document biophysicist and professor Robert K. Mortimer's research in the genetics of yeast and related organisms. Of interest in this collection are Mortimer's notebooks from the 1950s, and his materials documenting the Yeast Genetics Stock Center.

Language(s) of collection


Collection number:


Historical Note

The laboratory was founded as the University of California Radiation Laboratory in 1931 by Ernest Orlando Lawrence, a University of California Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It is a United States Department of Energy National Laboratory, operated by the University of California. The name changed to Lawrence Berkeley National Laboratory in 1995.

Biophysicist Robert K. Mortimer (Ph.D., University of California, Berkeley, 1953) was assistant professor of genetics at Berkeley beginning in 1956, became full professor in 1966, chaired the division of medical physics from 1972 to 1978, and served as chair of the Department of Biophysics and Medical Physics from 1984 to 1987. He also was affiliated with Lawrence Berkeley National Laboratory, where he served for a year as acting director of the lab's Human Genome Project.

Mortimer came to Berkeley in the early 1950s to study the impact of radiation on the survival of cells. He created strains of yeast with multiple copies of each chromosome, and discovered that more chromosomes led paradoxically to greater X-ray sensitivity. This led to his studies of the cell processes that protect them from physical and chemical damages to their DNA. The RAD genes discovered in these studies are the foundation of most contemporary studies of how higher cells repair damage to their DNA.

By the mid-1970s, Mortimer had created a genetic map of a yeast (Saccharomyces) with multiple mutations marking all the chromosomes, which he used to research how x-rays cause cell death. Even with a workable genetic map, Saccharomyces would have failed as an experimental organism except for another of Mortimer's innovations. Unlike other fungi whose spores are easy to isolated and cultivate, the four spores from Saccharomyces’ spores are born in an ascus that seems to be armor plated. In 1959, Mortimer and his colleague Johnston discovered that one could use the digestive juice of a snail to break that armor and liberate the spores for genetic analysis, and it was then possible for one person to more easily analyze thousands of meioses.

This discovery led to the development of a gene conversion process in Saccharomyces, which allows the information on one chromosome to be copied into the homologous chromosome, replacing the information that was there. Mortimer and colleagues produced the wealth of data on gene conversion that eventually led to the methods that allow gene replacements to be done in many different organisms.

Yeast divide by budding, leading to populations of genetically identical cells, and in 1959 Mortimer and Johnston discovered that individual cells in a culture of yeast can have very different life spans, depending upon whether the cell is a mother cell or a bud. Mortimer’s work on yeast aging set the stage for the discovery of the first genes affecting aging, and whose function is conserved from yeast to metazoans.

Mortimer also created the free Saccharomyces stock center to house thousands of strains of yeast that he thought would be of interest to the scientific community. A researcher could request any strain, and pay only the shipping to send the strain. This generous service did much to create a culture of sharing which still characterizes the yeast genetic community to this day. In 2002 Mortimer received the George W. Beadle Award from the Genetics Society of America in recognition of his many contributions that created the community of approximately 10,000 yeast genetic researchers.

Following his official retirement from UC, Mortimer spent 10 years in affiliation with the University of Florence, where he researched the genetic properties of yeast strains used in wine production.

Scope and Contents of Collection

These records document LBL scientist and UC Berkeley professor Robert K. Mortimer's groundbreaking work with yeast.

These records document biophysicist and professor Robert K. Mortimer's research in the genetics of yeast and related organisms. Using yeast cells, Mortimer studied the impact of radiation on the survival of cells and discovered that an increase in chromosomes in a cell led paradoxically to greater x-ray sensitivity. This discovery led to his famous studies of the many processes that all cells have to protect them from various physical and chemical damages to their DNA. Indeed, the so called RAD genes that were discovered in these studies are the foundation of most contemporary studies of how higher cells repair damage to their DNA. Mortimer created the saccharomyces stock center, which housed the many thousands of strains of yeast that his group created and made these strains available for genetic research. Of interest in this collection are Mortimer's notebooks from the 1950s, and his materials documenting the Yeast Genetics Stock Center.

Restrictions on Use and Access

This collection requires permission for access. Please contact the repository for more information, via email at

Selected Search Terms

These papers have been indexed in the International Catalog of Sources for History of Physics and Allied Sciences (ICOS) using the following terms. Those seeking related materials should search under these terms.


Mortimer, Robert K.


Lawrence Berkeley Laboratory
Lawrence Berkeley Laboratory. Life Sciences Division
Lawrence Berkeley National Laboratory
Lawrence Berkeley Radiation Laboratory

Subject terms


Administrative Information


Finding Aid to the Lawrence Berkeley Laboratory Life Science Division technical records of Robert K. Mortimer, 1950-1999


American Institute of Physics Niels Bohr Library & Archives

One Physics Ellipse
College Park, MD 20740


Encoding Information

Machine-readable finding aid encoded by Melanie J. Mueller in 2012. Any revisions made to this finding aid occurred as part of the editing and encoding process.

Series I: Technical records of Robert K. Mortimer

Box 1 Folder 1 Yeast Project 5-1 Logbook, undated
Folder 2 Yeast Project 5-2 Logbook, undated
Folder 3 Yeast Project 5-3 Logbook, undated
Folder 4 Research #1 Logbook, undated
Folder 5 Logbook #4 Yeast Research, undated
Folder 6 Research #5 Logbook, undated
Folder 7 Research #6 [Logbook], undated
Folder 8 Research #7 Gamma-Ray Pinhole Camera, undated
Folder 9 Logbook #9 Yeast Radiobiology, undated
Folder 10 R.K. Mortimer Research #15 Logbook, 1956
Folder 11 Research #16 [Logbook], undated
Folder 12 Research #18 Logbook, undated
Folder 13 Logbook #21, undated
Folder 14 Mortimer Dissertation: Cytological and Environmental Factors Related to the Effects of Radiations on Yeast Cells, undated
Folder 15 Correspondence, 1967-1968
Folder 16 Lindegren [Correspondence], 1967
Folder 17 Stock Center Research - Survival of Strains from Milk-Replica Storage - J. Bassell, 1973
Folder 18 Yeast Stock Center Protocol for Stock Storage Technique, 1975
Folder 19 Procedure for Preservation of Yeast Cultures - Procedure for Reviving Strains - SC and SM, undated
Folder 20 Stock Center, 1976-1977
Folder 21 DOE 189, 1977
Folder 22 DOE 189, 1978
Folder 23 DOE 189 (1978) 3669-18, 4419-01, 1978
Folder 24 SNC, undated
Folder 25 189 C.V., undated
Box 2 Folder 1 Request for Granting to NSF for YGSC, 1977, 1978, 1979, 1982
Folder 2 YGSC (1981-) Fermentation - Petite, 1981-
Folder 3 YGSC (1981-) Mapping (Sample) - Diploids, 1981-
Folder 4 YGSC (1981-) Nutritional Testers Adc-His, 1981-
Folder 5 YGSC (1981-) Nutritional Testers IW-URA, 1981-
Folder 6 YGSC (1981-) Suppressible Alleles - Sterile Yeast Mutants, 1981-
Folder 7 YGSC (1981-) Temp Sensitive Lethals Prot. Synth - rNA Synth, 1981-
Box 3 Folder 1 YGSC (1981-) Temp Sensitive Lethals (undefined) Factor, 1981-
Folder 2 YGSC (1981-) Wild Type - Mapping (Multiply), 1981-
Folder 3 Isabel, Francois Correspondence, 1980s
Folder 4 Correspondence with John Wood, Lily Research Laboratories / MBS, 1983
Folder 5 Final Completion Report to SPO for YGSC, 1981-1984, 1979-1981
Folder 6 YGSC Grant Proposal to NSF and Letters of Review - Grant, 1984
Folder 7 Renewal of Grant YGSC, 1984
Folder 8 Correspondence Regarding ATCC and Stock Centers, 1984
Folder 9 Grant Proposal for Renewal to NSH OF, 1984-1987
Folder 10 Progress Report YGSC, 1985-1986
Folder 11 YGSC NSF Propsal, 1987
Folder 12 YGSC NIH Proposal 1987, Award Letter, 1987
Folder 13 Lists of Users of YGSC 1984, 1985, 1987; Letter to Louise Ramm, NIH February 16, 1988, 1984-1988
Folder 14 Becky C. and J.J. [Yeast Genetic Stock Center Materials], 1986
Folder 15 Miscellaneous Correspondence YGSC, 1988-
Folder 16 Progress Report (July) NIH and Grant Award for Second Year (September), 1988
Folder 17 NIH Progress Report (July) and Grant Award for Third Year, 1989
Folder 18 NIH Renewal Continuation (1990-1991) and Award Letter, undated
Folder 19 Yeast Genetic Stock Center ASM Meeting Dallas, May 1991
Folder 20 Culture Collections - Dallas - Meeting, May 1991
Folder 21 Tables Map, May 1991
Folder 22 NIH Awards for Five Years, July 1991
Folder 23 RKM - Basel, Switzerland - Correspondence with Lab, etc., July-November 1991
Folder 24 Animal Resources Bulletin Request for Information and Our Reply - Application to US Fed of Culture Collect (June) - Publication to Guide to Grants and Dollars, 1991
Folder 25 Award Letters, NIH Grant Proposal 1991, NTCC 1993 Directory Federal Lab 1993 Letter Making Alex Nichols PI, 1991-1993
Folder 26 YGSC UC Berkeley Correspondence, 1991
Folder 27 Correspondence and Support Items for 1994 NIH YGSC Renewal, 1994
Folder 28 Progress Report Award Letter, 1994
Folder 29 YGSC NIH 1994 Report Final - Awarded 1995 for 1996, July 21, 1995
Folder 30 1994 Progress Report Tables, 1994
Folder 31 Support for 1995 YGSC Progress Report, 1995
Folder 32 Directories YGSC, 1997
Folder 33 [Stock Center Data?], undated
Box 4 Folder 1 [Stock Center Data?], undated
Folder 2 [Index Cards - Stock Center?], undated
Folder 3 B. Kirsop Correspondence for YGSC Catalogue, etc., 1987
Folder 4 Stock Center Catalogue, 1975
Folder 5 Genetic Map for Stock Center Catalogue, 1987
Folder 6 Stock Center Catalogue 6th Edition, October 1987
Folder 7 Stock Center Catalogue 6th Edition, October 1987
Folder 8 Stock Center Catalogue 7th Edition, 1991
Folder 9 Stock Center Catalogue 8th Edition, 1995
Folder 10 Stock Center Catalogue 8th Edition, 1995
Folder 11 Time Sheets Becky, 1986-1992
Folder 12 ACACIA, undated
Folder 13 [Wine] 1993, undated
Folder 14 [Wine] 1994, undated
Folder 15 Florence [Correspondence], 1994-1995
Folder 16 Correspondence with Bacardi and Jim Brand, 1995
Folder 17 [Mortimer-Contopoulou Correspondence], 1996
Folder 18 South Africa Strains, 1996-1997
Folder 19 STAR Project Communications with Alexis - Correspondence Italy, 1996
Folder 20 Entian Florence - Arrangements for Transferring Stock, 1997
Folder 21 Bernard Prior - Glycerol, undated
Folder 22 Vintage Data Sheet, 1996
Folder 23 LALL X XPB3, 1998
Folder 24 Fatty Acids, undated
Folder 25 Stuck Fermentation, 1998
Folder 26 Fermentations Prove Di Fermentazioni, undated
Folder 27 Protocols / Perugia - Strains / S.P. Wine Yeast (spore to spore) / Auxtrophic Marker Crosses / Wine Yeast, undated
Folder 28 Amber Suppressor, undated
Folder 29 Far Niente / Grape Berries / Flavonoids - Antociani, undated
Folder 30 PDM Brushing, undated
Folder 31 PDM - Brushing Program, undated
Box 5 Folder 1 Imcroci Fiorentini XMP 1014, undated
Folder 2 Mormoniella Logbook, undated
Folder 3 Logbook, undated
Folder 4 ar4 tr5 ad6 Fine Structure Mapping, undated
Folder 5 [Firenze Logbook], 1992-1993
Folder 6 Firenze [Logbook], 1996-1997
Folder 7 [Firenze Logbook], 1998
Folder 8 Firenze [Logbook], 1999
Folder 9 Ba Strains, undated
Folder 10 [Wine Notebook], undated
Folder 11 1995 Florence [Logbook], 1995
Folder 12 Viewgraphs, undated
Folder 13 Proposal: Studies on Stuck Fermentations, 1998-1999
Folder 14 Office of Technology Licensing, undated
Folder 15 Tom Stickel Emails re: Venture Capital, undated
Folder 16 Genome Reviews, undated
Folder 17 Office of Technology Transfer: Proprietary Information, undated
Folder 18 Correspondence with Gordon Burns, undated
Folder 19 ATCC, undated
Folder 20 AVF, undated
Folder 21 Patents, undated