The CellRaft™ Technology provides a cost-effective method to isolate and recover single cells for direct analysis, for the generation of clonal populations, or for on-array functional analysis. The working principle of the CellRaft Technology is schematically shown in the sidebar.
Microfabricated from an elastomeric material, the CytoSort™ Array is a high density microwell array with thousands of individual wells. Each microwell contains a raft – the CellRaft – that is held securely within the array. Within the array, the rafts serve as releasable culture sites for individual cells or colonies. The entire array is housed in a plastic cassette similar to a Petri dish, making it familiar to the biological research community.
Cells are plated on the CytoSort Array in the same manner as a standard tissue culture dish. The cells settle into the microwells and attach to the CellRaft within each microwell. Cells placed on the CytoSort Array are localized on the CellRaft surface and remain viable. The cells remain positioned on specific rafts while in culture so that single cells can be isolated or expand on the array into clonal colonies.
Individual CellRafts containing single cells of interest are identified using brightfield or fluorescence and a probe is used to release the target CellRaft. The probe pushes through the compliant polymer substrate of the CytoSort Array and dislodge an individual raft with its attached cell(s) (e.g. GFP+ cells in Fig. B).
The released CellRaft, which contains paramagnetic nanoparticles, is then recovered using a magnetic wand and transported to a 96-well plate or PCR tube. This procedure achieves cell isolation and recovery with excellent viability and purity. For example, single-cell cloning efficiencies of greater than 95% have been realized with 100% purity. The CellRaft™ Technology offers a high degree of flexibility as cells may be selected using a wide variety of criteria, including temporal and spatial characteristics, and requires only a very small sample size to conduct an experiment. The recovered cells can be used for direct analysis (e.g. PCR, MALDI, SDS-PAGE), or clonal expansion as shown in the sidebar.
CytoSort Arrays in different formats are often matched to specific applications. For example, 100 x 100 micron CytoSort Arrays with a single reservoir are often used for isolating single nuclei for downstream molecular analysis. CytoSort Arrays with a “quad” reservoir are the best choice for isolation and recovery of single cells or clonal expansion under differing culture media using a single cassette. Cell Microsystems offers a range of array products suitable for different applications, or if your needs are unique we provide a custom fabrication service for special purpose products.