Droplets- and digital-based methods

Fielden, P.R. and Baldock, S.J. (2019) Droplets- and digital-based methods. In: Encyclopedia of Analytical Science. Elsevier, pp. 225-231. ISBN 9780081019832

Abstract

Liquid droplets may be manipulated within microfluidic channel structures, or on planar surfaces to provide experimental platforms where each droplet is a discrete experimental entity. Sometimes described as digital methodology, this provides a unique approach within the fields of chemistry and biochemistry. Subsequent splitting, combining and sorting processes with the droplets offer a limitless opportunity for complex experimental design that includes high sample numbers with high-throughput capability. Distinct advantages include nanolitre, or lower sample volumes, rapid mixing and short diffusion distances. When placed within an automated microfluidic environment, droplets may be driven sequentially or in parallel through a pre-set pattern of unit operations. Many applications have been reported that include the broad fields of synthesis and sample assay. Synthetic applications have been reported for organic synthesis, biochemical synthesis and materials synthesis. The majority of assay-based applications have been reported for bio-assays and biological assays with single cells. The distinct advantages of low sample volumes and high-throughput have been the primary drivers for the development of droplet and digital-based methods.