title: Reactions and fluidics in miniaturized natural convection systems.
abstract: Buoyancy-driven convection offers a novel and greatly simplified mechanism for generating continuous nonpulsatile flow fields and performing thermally activated biochemical reactions. In this paper, we build on our previous work by constructing a multiwell device incorporating an array of 35-microL cylindrical cavities to perform polymerase chain reaction (PCR) amplification of a 191-base pair fragment associated with membrane channel proteins M1 and M2 of the influenza-A virus in as little as 15 min with performance comparable to conventional thermocyclers. We also describe entirely new adaptations of convective flows by conducting a series of coordinated flow visualization and computational studies to explore the design of closed-loop systems to execute tunable thermocycling, pumping, and mixing operations in a format suitable for integration into miniaturized biochemical analysis systems. Using 15-microL convective flow loops, we are able to perform PCR amplification of the same 191-base pair fragment associated with the influenza-A virus, as well as a 295-base pair segment of the human beta-actin gene in a format offering an enhanced degree of control and tunability. These convective flow devices can be further scaled down to nanoliter volumes and are ideally suited as a platform for a new generation of low-power, portable microfluidic DNA analysis systems.
authors.affiliation: Department of Chemical Engineering, The University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Madhavi
authors.initials: M
authors.lastname: Krishnan
authors.forename: Nitin
authors.initials: N
authors.lastname: Agrawal
authors.forename: Mark A
authors.initials: MA
authors.lastname: Burns
authors.forename: Victor M
authors.initials: VM
authors.lastname: Ugaz
mesh_terms: D000199:Actins / Q000737:chemistry; D001483:Base Sequence; D017931:DNA Primers; D006801:Humans; D008904:Miniaturization; D016133:Polymerase Chain Reaction
chemical_list: D000199:Actins; D017931:DNA Primers