title: A tetra-layer microfluidic system for peptide affinity screening through integrated sample injection.
abstract: A novel integrated microfluidic system was designed and fabricated for affinity peptide screening with in situ detection. A tetra-layer microfluidic hybrid chip containing two top eccentric diffluent layers, an inter-layer and a bottom screening layer, was developed as the core device of the system. The eccentric diffluent layers were ingeniously invented for the vertical sample delivery from 2 top-inlets into 12 bottom-inlets, which eliminated the use of excessive accessories and complicated pipelines currently used in other systems. By using six pH gradient generators, the magnetic bead-based screening in 36 parallel chambers was simultaneously carried out under 6 different pH conditions from 5.4 to 8.2. This allowed simultaneous screening of 6 compounds and each under 6 different pH conditions. The fabricated chip system was applied to screening of affinity peptides towards β-endorphin antibody. The affinities of the peptide ligands to the antibody were assessed by on-chip confocal detection. The results from the screening study using this system indicated that the pentapeptide with the sequence of YGGFL had the highest affinity towards β-endorphin antibody at pH 7.1, which was further confirmed by the ELISA assay using a 96-well plate format. This microfluidic screening system is automatic, low-cost and reusable for not only peptide screening but also other bioactive compounds screening towards target molecules.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, 100190 Beijing, PR China.
authors.forename: Weizhi
authors.initials: W
authors.lastname: Wang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Huang
authors.forename: Yulong
authors.initials: Y
authors.lastname: Jin
authors.forename: Guoquan
authors.initials: G
authors.lastname: Liu
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Huimin
authors.initials: H
authors.lastname: Ma
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation; D004867:Equipment Design; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay / Q000295:instrumentation; D017404:In Situ Hybridization, Fluorescence / Q000295:instrumentation; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D010455:Peptides / Q000032:analysis*
chemical_list: D010455:Peptides