title: High-resolution multiphoton cryomicroscopy.
abstract: An ultracompact high-resolution multiphoton cryomicroscope with a femtosecond near infrared fiber laser has been utilized to study the cellular autofluorescence during freezing and thawing of cells. Cooling resulted in an increase of the intracellular fluorescence intensity followed by morphological modifications at temperatures below -10 °C, depending on the application of the cryoprotectant DMSO and the cooling rate. Furthermore, fluorescence lifetime imaging revealed an increase of the mean lifetime with a decrease in temperature. Non-destructive, label-free optical biopsies of biomaterial in ice can be obtained with sub-20 mW mean powers.
authors.affiliation: JenLab GmbH, Schillerstrasse 1, 07745 Jena, Germany; Department of Biophotonics and Laser Technology, Saarland University, Campus A5.1, 66123 Saarbrücken, Germany. Electronic address: koenig@jenlab.de.
authors.forename: Karsten
authors.initials: K
authors.lastname: König
authors.affiliation: Department of Biophotonics and Laser Technology, Saarland University, Campus A5.1, 66123 Saarbrücken, Germany.
authors.forename: Aisada
authors.initials: A
authors.lastname: Uchugonova
authors.affiliation: JenLab GmbH, Schillerstrasse 1, 07745 Jena, Germany; Department of Biophotonics and Laser Technology, Saarland University, Campus A5.1, 66123 Saarbrücken, Germany.
authors.forename: Hans Georg
authors.initials: HG
authors.lastname: Breunig
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D015925:Cryopreservation; D006801:Humans; D007700:Kinetics; D018613:Microscopy, Confocal / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods
keywords: Biobank; Cryomicroscope; Cryopreservation; FLIM; Freezing; Multiphoton imaging; Two-photon