title: Pressure stabilizer for reproducible picoinjection in droplet microfluidic systems.
abstract: Picoinjection is a promising technique to add reagents into pre-formed emulsion droplets on chip however, it is sensitive to pressure fluctuation, making stable operation of the picoinjector challenging. We present a chip architecture using a simple pressure stabilizer for consistent and highly reproducible picoinjection in multi-step biochemical assays with droplets. Incorporation of the stabilizer immediately upstream of a picoinjector or a combination of injectors greatly reduces pressure fluctuations enabling reproducible and effective picoinjection in systems where the pressure varies actively during operation. We demonstrate the effectiveness of the pressure stabilizer for an integrated platform for on-demand encapsulation of bacterial cells followed by picoinjection of reagents for lysing the encapsulated cells. The pressure stabilizer was also used for picoinjection of multiple displacement amplification (MDA) reagents to achieve genomic DNA amplification of lysed bacterial cells.
authors.affiliation: Sandia National Laboratories, Biotechnology and Bioengineering Department, Livermore, CA, USA. rmeaghe@sandia.gov aksingh@sandia.gov.
authors.forename: Minsoung
authors.initials: M
authors.lastname: Rhee
authors.forename: Yooli K
authors.initials: YK
authors.lastname: Light
authors.forename: Suzan
authors.initials: S
authors.lastname: Yilmaz
authors.forename: Paul D
authors.initials: PD
authors.lastname: Adams
authors.forename: Deepak
authors.initials: D
authors.lastname: Saxena
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Meagher
authors.forename: Anup K
authors.initials: AK
authors.lastname: Singh
mesh_terms: D004247:DNA; D004867:Equipment Design; D004926:Escherichia coli; D005456:Fluorescent Dyes; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008845:Microinjections / Q000295:instrumentation*; D011312:Pressure
chemical_list: D005456:Fluorescent Dyes; D004247:DNA