title: Microarray-to-microarray transfer of reagents by snapping of two chips for cross-reactivity-free multiplex immunoassays.
abstract: Whereas microarray and microfluidic technologies have progressed on many fronts, servicing microchips with minute amounts of reagents still constitutes an important challenge for many applications. Recently, chip-to-chip reagent transfer methods were introduced that simplify the delivery of reagents but required manual, visual alignment, custom-built microwells, and only showed the reaction of a single sample with multiple chemicals. Here, we present the snap chip, which uses common glass slides for transfer, back-side alignment for achieving precise alignment in spite of mirroring, and a snap-apparatus for facile transfer of arrays of chemicals at once by snapping the two slides together. We recently established that cross-reactivity was a significant problem in multiplex assays both theoretically and experimentally and found that it can be eliminated by avoiding mixing, but which necessitates delivering each detection antibody to a single spot with the cognate capture antibody. Using the snap chip, multiplexed sandwich immunoassays without mixing were performed: a slide with multiple arrays of 10 different capture antibodies was incubated with a sample, and then all detection antibodies transferred at once by snapping, each to the single cognate spot. All binding curves were established and limits of detection in the pg/mL range were obtained. Snap chips were stored up to 3 months prior to usage. The snap chip, by dissociating microarray production, which requires expensive equipment, from assay execution, which can be achieved using a hand-held alignment apparatus, will allow for multiplex reactions to be performed using a user-friendly kit. This new liquid handling format can be easily adapted to other applications that require transfer of minute amounts of different reagents in parallel.
authors.affiliation: Biomedical Engineering Department, McGill University and Genome Quebec Innovation Centre, McGill University, Montréal, QC, H3A 1A4, Canada.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Li
authors.forename: Sébastien
authors.initials: S
authors.lastname: Bergeron
authors.forename: David
authors.initials: D
authors.lastname: Juncker
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D005898:Glass; D006041:Goats; D006801:Humans; D007118:Immunoassay; D007202:Indicators and Reagents; D057230:Limit of Detection; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods; D040081:Protein Array Analysis / Q000295:instrumentation / Q000379:methods; D011485:Protein Binding; D011506:Proteins / Q000032:analysis* / Q000276:immunology; D011817:Rabbits
chemical_list: D000906:Antibodies; D007202:Indicators and Reagents; D011506:Proteins