The individual-cell-based cryo-chip for the cryopreservation, manipulation and observation of spatially identifiable cells. II: Functional activity of cryopreserved cells
1 Main Department for Biophysics and Cryotechnology, Fraunhofer IBMT, Ensheimer Straβe 48, 66386 St. Ingbert, Germany
2 The Biophysical Interdisciplinary Schottenstein Center for the Research and Technology of the Cellome, Bar-Ilan University, Ramat Gan, 52900, Israel
3 GeSiM mbH, Bautzner Landstraβe 45, 01454 Groβerkmannsdorf, Germany
4 WBT Ltd., POB 1516, Ramat Gan, 52115, Israel
5 Zentrum für gynäkologische Endokrinologie und Reproduktionsmedizin, Kaiserstrasse 5-7, 66111 Saarbrücken, Germany
6 Professorship for Molecular and Cellular Biotechnology/Nanotechnology, University of Saarland, 66041 Saarbrücken, Germany
BMC Cell Biology 2010, 11:83 doi:10.1186/1471-2121-11-83Published: 25 October 2010
The cryopreservation and thawing processes are known to induce many deleterious effects in cells and might be detrimental to several cell types. There is an inherent variability in cellular responses among cell types and within individual cells of a given population with regard to their ability to endure the freezing and thawing process. The aim of this study was to evaluate the fate of cryopreserved cells within an optical cryo apparatus, the individual-cell-based cryo-chip (i3C), by monitoring several basic cellular functional activities at the resolution of individual cells.
In the present study, U937 cells underwent the freezing and thawing cycle in the i3C device. Then a panel of vital tests was performed, including the number of dead cells (PI staining), apoptotic rate (Annexin V staining), mitochondrial membrane potential (TMRM staining), cytoplasm membrane integrity and intracellular metabolism (FDA staining), as well as post-thawing cell proliferation assays. Cells that underwent the freezing - thawing cycle in i3C devices exhibited the same functional activity as control cells. Moreover, the combination of the multi-parametric analysis at a single cell resolution and the optical and biological features of the device enable an accurate determination of the functional status of individual cells and subsequent retrieval and utilization of the most valuable cells.
The means and methodologies described here enable the freezing and thawing of spatially identifiable cells, as well as the efficient detection of viable, specific, highly biologically active cells for future applications.