Selection and isolation of single cells from a mixed population is a common procedure, for example, during the development of clonal cell lines that are genetically engineered, derived from stem cells, or grown from patient samples, single cells must be isolated and then cloned to form a homogeneous population. While myriad methods exist, they commonly rely on enzymatic or mechanical release, which imposes drawbacks in terms of loss of cell morphology, removal of cell surface markers, damage to cell membranes, alterations in cellular physiology, and loss of viability. In this seminal work describing the CellRaft® Technology, the authors demonstrate the fabrication of a microwell array that possesses detachable concave elements, termed CellRafts®, using a PDMS mold combined with standard dip-coating procedures. The resulting microarrays have low auto-fluorescence and are easily removable, in a targeted fashion, allowing for isolation and clonal expansion of single cells. Furthermore, the CellRaft™ Arrays allow for the assessment of cells based on morphology in a time-resolved manner and can be tailored to workflows requiring few to hundreds of thousands of cells.
