Frederick Kleinhans Ph.D.

Associate Professor, Emeritus, Physics


  • B.S., Physics, University of Michigan, Ann Arbor, MI 1965
  • Ph.D., Physics, Ohio State University, Columbus, OH, 1971

Current Research

My research is a collaborative effort with a number of biologists who are working on several cryobiological problems.  Cryobiology has seen wide use for efficient preservation of genetic mutants used in medical research (e.g. mice), assisted reproduction in humans and animals (e.g. the dairy industry), organ transplantation (e.g. pancreatic islet cells), and preservation of endangered species (e.g. the black-footed ferret). But no, not human heads or bodies.  We are trying to improve existing cryopreservation protocols and develop new ones for several cell types. Typically, successful cryopreservation requires the efficient removal of cell water and the introduction of cryoprotectants, e.g. glycerol, without osmotic damage or toxic injury. Thus it is useful to know the osmotic characteristics, water permeability (Lp), and solute permeability (Ps) of target cell membranes in order to model their response and optimize cryopreservation protocols. My work deals with understanding passive membrane transport, the design and analysis of membrane permeability experiments, and modeling cell responses.

Currently we are working on achieving or improving the cryopreservation of several species including coral larvae, zebrafish embryos and sperm, , monkey sperm, oyster oocytes, and other marine species of aquaculture interest.   We are also investigating the fundamental mechanisms of cryo damage using mouse embryos and plant protoplasts.  Specifically, what event triggers the generally lethal formation of intracellular ice?  Cells typically do not freeze at their thermodynamic freezing point, but rather undergo supercooling which can reach ten's of degrees C.  It is still not understood what drives intracellular nucleation of this super cooled water.

Current collaborators include Drs. Peter Mazur, University of TN, Knoxville; Mary Hagedorn, National Zoological Park, Washington, DC, and the Hawaii Institute of Marine Biology, Oahu, HI; Stuart Meyers, UC Davis, CA; Serean Adams, Cawthron Institute, New Zealand; and Keisuke Edashige and Magosaburo Kasai, Kochi University, Japan.  My work is funded via subcontracts with my collaborators who are currently funded by NIH, Friends of the (National) Zoo, and the Cawthron Institute.

Select Publications

Recent Publications (Publications and Reprints)

Kleinhans FW, Seki S, Mazur P. (2010)
Simple, inexpensive attainment and measurement of very high cooling and warming rates.
Cryobiology.  61, 231-233.

Hagedorn M, Carter VL, Leong JC, Kleinhans FW. (2010)
Physiology and cryosensitivity of coral endosymbiotic algae (Symbiodinium).
Cryobiology. 60, 147-158.

Hagedorn M, Carter VL, Ly S, Andrell RM, Yancey PH, Leong JA, Kleinhans FW. (2010)
Analysis of internal osmolality in developing coral larvae, Fungia scutaria.
Physiol Biochem Zool.  83,157-166.

Kleinhans FW, Mazur P. (2009)
Determination of the water permeability (Lp) of mouse oocytes at -25 degrees C and its activation energy at subzero temperatures.
Cryobiology 58, 215-224.

Seki S, Kleinhans FW, Mazur P. (2009)
Intracellular ice formation in yeast cells vs. cooling rate: predictions from modeling vs. experimental observations by differential scanning calorimetry.
Cryobiology 58, 157-165 (2009).

Hagedorn M, Ricker J, McCarthy M, Meyers SA, Tiersch TR, Varga ZM, and Kleinhans FW. (2009)
Biophysics of zebrafish (Danio rerio) sperm.
Cryobiology 58, 12-19.

Kleinhans FW and Mazur P (2007)
Comparison of actual vs. synthesized ternary phase diagrams for solutes of cryobiological interest.
Cryobiology 54, 212-222.

Yamaji Y, Valdez DM Jr, Seki S, Yazawa K, Urakawa C, Jin B, Kasai M, Kleinhans FW and Edashige K (2006)
Cryoprotectant Permeability of Aquaporin-3 Expressed in Xenopus Oocytes.
Cryobiology 53 , 258-267.

Kleinhans FW, Guenther JF, Roberts DM and Mazur P(2006)
Analysis of Intracellular Ice Nucleation in Xenopus Oocytes by Differential Scanning Calorimetry.
Cryobiology 52 , 128-138.

Hagedorn M, Pan R, Cox EF, Hollingsworth L, Krupp D, Lewis TD, Leong JC, Mazur P, Rall WF, Macfarlane DR, Fahy G and Kleinhans FW (2006)
Coral Larvae Conservation: Physiology and Reproduction.
Cryobiology 52 , 33-47.