We are one of the few places in the UK with access to the versatile LEAP technology, which provides high-throughput microplate imaging of live cells in-situ, with laser-mediated cell processing capabilities. Cell populations can be selected by user-defined parameters, allowing elimination of unwanted cells, and optoinjection of a wide range of macromolecules into specific cell populations.
Brightfield imaging is LED-based, while multicolour fluorescence utilises a hybrid-halide lamp with 8 excitation and 8 emission filters, coupled to a CCD camera. Magnification is adjustable with 3x, 5x, 10x, and 20x available. Multi-wavelength imaging is integrated with software allowing cell characterisation and population selection by fluorescence intensity, size, granularity and shape.
Pulsed lasers are used only in cell processing (no imaging), with 2 wavelengths: 355nm (UV) & 532nm (Green). Laser targeting can be automated or manual, shooting up to 1000 cells/sec.
In-well elimination of unwanted cells with minimal effect on remaining cells has been used in fast and efficient selection of transduced gene expression, and in the generation of high-secreting cell clones. A range of mechanisms can be used in cell removal. Photothermal purification leads to immediate cell necrosis and protein coagulation (minimising cell contents leakage), Photomechanical purification leads to immediate cell lysis, and photochemical processing to targeted cell apoptosis over 4-24h.
Laser-mediated optoinjection is particularly useful for difficult-to-transfect cell types, including primary cells. Pulsed laser targeting leads to transient cell permeabilisation, allowing delivery of a variety of macromolecules including plasmid DNA, siRNA, peptides and small proteins. Off-target effects are reduced with minimal effects on cell viability, compared with lipofection and electroporation.
Stem cell colony passage
Generates identically-sized embryoid bodies without the use of collagenase or other enzyme dissociation. Photothermal “cutting” of cell layers minimises cell loss. This technique has has been shown to maintain a high level of downstream differentiation potential.
If you think the LEAP platform could assist with your research goals, please contact Dr. Caroline Wardrope to discuss your project:
UK Centre for Mammalian Synthetic Biology
3.11 CH Waddington Building
University of Edinburgh