Miniaturizing chemistry and biology in microdroplets

Abstract

By compartmentalizing reactions in aqueous microdroplets of water-in-oil emulsions, reaction volumes can be reduced by factors of up to 10(9) compared to conventional microtitre-plate based systems. This allows massively parallel processing of as many as 10(10) reactions in a total volume of only 1 ml of emulsion. This review describes the use of emulsions for directed evolution of proteins and RNAs, and for performing polymerase chain reactions (PCRs). To illustrate these applications we describe certain specific experiments, each of which exemplifies a different facet of the technique, in some detail. These examples include directed evolution of Diels-Alderase and RNA ligase ribozymes and several classes of protein enzymes, including DNA polymerases, phosphotriesterases, beta-galactosidases and thiolactonases. We also describe the application of emulsion PCR to screen for rare mutations and for new ultra-high throughput sequencing technologies. Finally, we discuss the recent development of microfluidic tools for making and manipulating microdroplets and their likely impact on the future development of the field.

Interfacial Phenomena and Fluid Control in Micro/Nanofluidics

“…[58][59][60][61][62][63][64][65] Many well-written review articles have been published on the subject of droplet flow. 9,[66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81] In this review, parallel two-phase flow 6,[82][83][84][85] is considered with respect to the roles of liquid interfaces for the sake of simplified physical descriptions.…”

Syringe-vacuum microfluidics: A portable technique to create monodisperse emulsions

“…[1][2][3] With the devices, the drops are loaded with cells, incubated to stimulate cell growth, picoinjected to introduce additional reagents, and sorted to extract rare specimens. [4][5][6] This allows biological reactions to be performed with greatly enhanced speed and efficiency over conventional approaches: by reducing the drop volume, only picoliters of reagent are needed per reaction, while through the use of microfluidics, the reactions can be executed at rates exceeding hundreds of kilohertz.…”

Basic Technologies for Droplet Microfluidics

“…Applications of droplets in chemical reactions, particle synthesis, and single cell analysis will also be briefly reviewed. The readers are also addressed to some recent excellent reviews on various aspects of droplet microfluidics [5][6][7][8][9][14][15][16][17]. Studies from fluid mechanics perspectives, which focus on the understanding of the basic fluid dynamic phenomena involved in droplet or multiphase microfluidics in general, have been summarized in recent reviews [18][19][20][21] and are not detailed here.…”

“…Later on theoretical interests arose on the characterization and exploration of complex dynamic phenomena involved in droplet generation and trafficking within microfluidic channel networks [3,4]. Meanwhile, a wealth of technologies for improved droplet generation, intra-droplet content manipulation, and methods for controlled trafficking, all enabled a wide range of appealing applications [5][6][7][8] from chemical kinetics [9] and protein 70 S. Zeng et al crystallization [10,11] to material synthesis [12,13], single cell analysis [14,15], polymerase chain reaction (PCR) [16], protein engineering, and high throughput screening technologies [17]. This review will discuss the recent advances in technologies that enable droplets as microreactors with complete functions and the applications of droplets in chemistry and biology.…”