From single-molecule detection to next-generation sequencing: microfluidic droplets for high-throughput nucleic acid analysis

摘要

Physical and chemical variables in droplet-based experiments: ( ) Temperature can be controlled over wide ranges, enabling PCR in emulsions; ( ) Hydrophobic substrates or ligands can be delivered through the oil phase into aqueous droplets; ( ) Water-soluble components can be delivered through nanoscale droplets or swollen micelles, allowing the regulation of biochemical processes; ( ) Internal pH can be altered, for example, by the delivery of acetic acid; ( ) Photocaged substrates and ligands can be introduced into the droplets during emulsification and photoactivated at later times. Adapted from Ref. (Griffiths and Tawfik ) with permission, copyright© 2006 Elsevier. Device geometry and mechanism of drop formation through confinement gradients. Such an approach allows high-throughput production of controlled emulsions. Images show an emulsion containing droplets with variable payloads but constant size. Adapted from Ref. (Dangla et al. ) with permission, copyright© 2013 PNAS. 1-million droplet array for dPCR contains one droplet generator, 256 splitters and a 27 mm × 40.5 mm viewing chamber. Adapted from Ref. (Hatch et al. ) with permission, copyright© 2011 RSC