Bioindicator "fingerprints" of methane-emitting thermokarst features in Alaskan soils.

Permafrost thaw increases the bioavailability of ancient organic matter, facilitating microbial metabolism of volatile organic compounds (VOCs), carbon dioxide, and methane (CH). The formation of thermokarst (thaw) lakes in icy, organic-rich Yedoma permafrost leads to high CH emissions, and subsurface microbes that have the potential to be biogeochemical drivers of organic carbon turnover in these systems. However, to better characterize and quantify rates of permafrost changes, methods that further clarify the relationship between subsurface biogeochemical processes and microbial dynamics are needed.

Dual primer emulsion PCR for next- generation DNA sequencing.

We have developed a highly sensitive single-molecule clonal amplification method called dual primer emulsion PCR (DPePCR) for next-generation DNA sequencing. The approach is similar in concept to standard emulsion PCR; however, in DPePCR both primers are attached to the beads, therefore following PCR amplification, both strands of the PCR products are attached to the beads. The ends of each strand can be freed for analysis by restriction digestion of the bridged PCR fragments, which allows efficient paired-end sequencing of fragment libraries.

Multiplex lateral-flow test strips fabricated by two-dimensional shaping.

We have fabricated paper- and nitrocellulose-based lateral-flow devices that are shaped in two dimensions by a computer-controlled knife. The resulting star, candelabra, and other structures are spotted with multiple bioassay reagents to produce multiplex lateral-flow assays. We have also fabricated laminar composites in which porous nitrocellulose media are sandwiched between vinyl and polyester plastic films.