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Photo of Chris Frethem

Chris Frethem

Electron Microscopy Specialist

(612) 624-4652


B.S.   Biology, University of Minnesota, Minneapolis, MN

Professional Experience

2003 - present Scientist, I.T. Characterization Facility, U of M
1993 - 2003 Scientist, Dept. of Genetics, Cell Biology, and Development, U of M
1984 - 1993 Associate Scientist, Dept. of Cell Biology and Neuro,. U of M
1978 - 1984 Jr. Scientist, Dept. of Anatomy, U of M
1977 - 1978 Pr. Lab Tech, Dept. of Surgical Pathology, U of M

Professional Societies

  • Minnesota Microscopy Society
  • Microscopy Society of America


  • Erlandsen, S., Chen, Y., Frethem, C., Detry, J., and Wells, C., 2003, High Resolution Backscatter Electron Imaging of Colloidal Gold in LVSEM, J. Microscopy
  • Erlandsen, S.L., Y. Chen, C. Ottenwaelter, and C. Frethem., (2001) Cryo Field Emission SEM. BioTechniques, 31:300-305
  • Erlandsen, S.L., Chen, Y., and Frethem, C., (2000) Field Emission Scanning Electron Microscopy (FESEM) Entering the 21st Century: Nanometer Resolution and Molecular Topography of Cell Structure. J. Histotechnology, 23: (3) 249-259.
  • Erlandsen, S.L., Frethem, C., and Wells, C.L., (1995) Backscatter Electron Imaging with FESEM: A New Way to Look at Cell Surface Topography and Immunogold Labeling. Views EM [Texas A&M University] 10:4-7.
  • Frethem, C., C. Wells, V. Carlino, and S.L.Erlandsen, (1993) High Resolution Field Emission SEM (FESEM) of Bulk Biological Samples: Relationship Between Different Metal Coatings, Their Thicknesses, and Quality of Backscatter Electron (BSE) Versus Secondary Electron (SE) Imaging. In: Proc. 51st Ann. Mtg. MSA (G.W. Bailey and C.L. Reider, eds.) San Francisco Press, San Francisco, CA, pp. 370-371.
  • Stoffel, M.H, Frethem, C., Hamilton, D.W., and Friess, A.E., (1993) Improved Preservation of Rat Epididymal Sperm for High-Resolution Low-Voltage Scanning Electron Microsopy (HR-LVSEM). Mol. Reprod. Develop. 34:175-182.
  • Erlandsen, S.L., Frethem, C., and Meyer, E.A., (1984) Scanning Electron Microscopy of Giardia lamblia Excystation. XI Inter. Cong. Trop. Med. and Malaria, Calgary, Alberta, Sept. 16-22.

In his more than 27 year involvement with electron microscopy at the U of MN, Chris has experienced many improvements in instrument technology, and changes in research emphasis, facilities management, and his own roles within the university's microscopy community.  As manager in the Nils Hasselmo Hall lab, he is responsible for operating, maintaining, and training users in the use of the JEOL 1200-EX II TEM, Hitachi S-900 and S-4700 FEGSEMs and their associated cryo sample preparation instruments, several sample coating instruments, the Balzers High Pressure Freezing System, BalTec Freeze-Fracture System, Balzers Freeze-Substitution System, and the Reichert UltraCut S Ultramicrotome.

Among his goals for the facility are to improve its ability to efficiently process and analyze a wider range of biological and materials sciences samples, to improve training methods and materials for specialists and non-specialists, to acquire essential new equipment, and to bring currently unused or underused instruments into service.