title: Minimum-step immuno-analysis based on continuous recycling of the capture antibody.
abstract: Most immuno-analytical systems employ antibodies that do not readily dissociate upon binding to its partner antigen (i.e., target analyte; α2-macroglobulin as a model) and, thus, either need to be disposed of after one-time use or be reused after binding has been reset. To achieve a minimum-step analysis, an antibody that is capable of rapidly reversible binding with high affinity to an antigen was investigated in this study. This antibody was immobilized on the surface of a label-free sensor, which was combined with microfluidic channels, to demonstrate its applicability. The antibody was successively reused without a regeneration step under physiological conditions, offered specific analysis in the serum medium, and detected the analyte at concentrations as low as 0.1 ng mL(-1), which could further be enhanced by 100-fold. The sensor response reached 95% equilibrium after 8.3 and 14.9 min in average on each dose level for the concentration increase and decrease, respectively. The dynamic range covered a 5 logarithmic analyte concentration. Since the sampling size was in the nanolitre to millilitre range per day under the conditions used and the sensor may retain a long shelf-life, it could potentially be used in a clinical setting for long-term, on-line monitoring of diseases.
authors.affiliation: Program for Bio-Microsystem Technology, Korea University, 204C Specific Research Wing, Biotechnology Building (Green Campus), 1, 5-ka, Anam-dong, Sungbuk-gu, Seoul, 136-701, Republic of Korea.
authors.forename: Hyun-Kyu
authors.initials: HK
authors.lastname: Cho
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Seo
authors.forename: Il-Hoon
authors.initials: IH
authors.lastname: Cho
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Paek
authors.forename: Dong-Hyung
authors.initials: DH
authors.lastname: Kim
authors.forename: Se-Hwan
authors.initials: SH
authors.lastname: Paek
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D046210:Microfluidic Analytical Techniques / Q000379:methods; D011485:Protein Binding; D000511:alpha-Macroglobulins / Q000032:analysis*
chemical_list: D055910:Antibodies, Immobilized; D000911:Antibodies, Monoclonal; D000511:alpha-Macroglobulins