Optical systems for single cell analyses

BACKGROUND: Data extracted from a population of cells represent the average response from all cells within the population. Even when the cells are genetically identical, cell-to-cell variations and genetic noise can make the cells respond in completely different ways. To understand the mechanisms behind the behaviour of a population, the cells must also be analysed on an individual basis. OBJECTIVE: This review highlights the use of optical manipulation, microfluidics and advanced fluorescence imaging techniques for the acquisition of single cell data. CONCLUSION: By implementation of these three techniques, it is possible to achieve a deeper insight into the principles underlying cellular functioning and a more thorough understanding of the phenomena often observed in cell populations, thus facilitating research in drug discovery.