Organs and tissues are composed of single cells or a group of cells with a unique function and identity. In general, a mix of heterogenous cell populations is used to report data, which is an average of the different cells. Even with cells in the same cell line or primary cell cultures it was proven that each cell has a different genome, transcriptome, proteome, and capacity to differentiate or respond to extracellular signals. Each cell has a unique identity; and their location, migration, and alteration of the surrounding extracellular matrix will modify that identity. Because the cells and tissues scale, it is a Herculean task to isolate individual cells (alive or fixed). For example, specific limbal stem cell markers can still not be used to identify these cells located near the palisades of Vogt. Interpatient cancer heterogeneity also exists, explaining the difference in the treatment efficacy. Progressive diseases are also heterogeneous, which could explain the difficulty to treat them or to develop new treatments (e.g., neurodegeneration). To achieve such results new technologies are required to be developed.

A lot of effort is made to develop tools to collect and isolate individual cells, but very few instruments are available. The topics of interest for this Methods Collection are methodologies, devices, or instruments to isolate individual cells or a group of cells from cell cultures, from normal or diseased tissues.