LIVE CELL IMAGING CHAMBERS
Cells are the building blocks of organisms and are dynamic objects that change shape and molecular organization in response to the environment. As a result of their plasticity, it is challenging to observe them microscopically while live-though live cell analysis offers many advantages over fixed cell analysis. There are now many fluorescent proteins and probes as well as sophisticated imaging systems available to observe live cells. Super-resolution microscopes enable time-lapse recording of cells with nano-scale resolution (Chi, 2009; Galbraith and Galbraith, 2011) and sophisticated software continues to improve image analysis and visualization in 3D. Despite the technological progress, the real challenge remains in obtaining and maintaining intact cells that represent relevant physiology (See Nikon MicroscopyU.)
The most critical factor in live-cell imaging is maintaining control of environmental conditions such as temperature, humidity and gas mixture, and pH. Thus many designs for imaging chambers have evolved for use with long-term experiments (>30 minutes) that require strict environmental control. For shorter experiments, either open or closed chambers may be used. For efficient experiments, the culture chamber must be sterile to avoid contamination that may affect normal biology, and amenable to high-resolution imaging, with high-quality glass with a low refractive index, and easily handled on standard microscope stages. The object is to conduct culture and imaging in one chamber that accommodates both activities with ease. Grace Bio-Labs has designed a variety of chambers and seals designed for live or fixed cell imaging. Our disposable chambers are constructed of high-quality, biocompatible material and manufactured with minimal particle contamination, and then shipped sterile. These chambers offer an economical alternative to expensive re-usable systems constructed of steel.
Recent examples of live cell imaging and super-resolution imaging include that of Rosa et al. (2013), who observed clustering of a transgenic allele from plants. The clustering of a specific locus on chromatin is responsible for inducing flowering is observed in response to cold, thus suppressing the expression of this gene. Live cell imaging was conducted using a SecureSeal™ from Grace Bio-Labs, attached to a gas-permeable membrane. Ribeiro et al. (2010) used fluorescence microscopy and single-molecule detection to localize proteins on kinetochore chromatin. Cells were observed in CoverWell™ chambers from Grace Bio-Labs to localize the CENP-H (Histone H3) protein in unfolded chromatin.
- Chi, KR, 2009. Super-resolution microscopy: breaking the limits. Nature Methods: 6, 15-18.
- Galbraith, CG, Galbraith, JA, 2011. Super-resolution microscopy at a glance. J.of Cell Science: 124:1607-11.
- Rosa, S., et al. 2013. Physical clustering of FLA alleles during Polycomb-mediated epigenetic silencing in vernalization. Genes & Development, 27: 1845-50.
- Ribeiro SA at al., 2010. A super-resolution map of the vertebrate kinetochore. PNAS, 107(23) 10484-489.