Cell Fixation by Light-Triggered Release of Glutaraldehyde.
Chemical fixation of living cells for microscopy is commonly achieved by crosslinking of intracellular proteins with dialdehydes prior to examination. We herein report a photocleavable protecting group for glutaraldehyde that results in a light-triggered and membrane-permeable fixative, which is nontoxic prior to photocleavage. Lipophilic ester groups allow for diffusion across the cell membrane and intracellular accumulation after enzymatic hydrolysis. Irradiation with UV light releases glutaraldehyde. The in situ generated fixative crosslinks intracellular proteins and preserves and stabilizes the cell so that it is ready for microscopy. In contrast to conventional glutaraldehyde fixation, tissue autofluorescence does not increase after fixation. Caged glutaraldehyde may in future enable functional experiments on living cells under a light microscope in which events of interest can be stopped in spatially confined volumes at defined time points. Samples with individually stopped events could then later be analyzed in ultrastructural studies.
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.|InnovationLab GmbH, Speyerer Strasse 4, 69115, Heidelberg, Germany.
Korwin M
KM
Schelkle
Center of Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany.
Christopher
C
Schmid
Center of Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany.|Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 229, 69120, Heidelberg, Germany.|CellNetworks, Single Molecule Spectroscopy, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.
Klaus
K
Yserentant
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
Markus
M
Bender
Center of Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany.
Irene
I
Wacker
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.|InnovationLab GmbH, Speyerer Strasse 4, 69115, Heidelberg, Germany.
Martin
M
Petzoldt
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.|InnovationLab GmbH, Speyerer Strasse 4, 69115, Heidelberg, Germany.
Manuel
M
Hamburger
Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 229, 69120, Heidelberg, Germany.|CellNetworks, Single Molecule Spectroscopy, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.
Dirk-Peter
DP
Herten
Institut für Pharmazie und Molekulare Biotechnologie, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 364, 69120, Heidelberg, Germany.
Richard
R
Wombacher
Center of Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany.|CellNetworks, Cryo Electron Microscopy, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.
Rasmus R
RR
Schröder
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.|Center of Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany.
Uwe H F
0000-0002-9369-5387
UH
Bunz
cell fixation; glutaraldehyde; microscopy; mitochondrial motion; photocleavage