title: Immobilized carboxymethylated dextran coatings for enhanced ELISA.
abstract: We here report the development of a new generation of enzyme-linked immunosorbent assay (ELISA) that takes advantage of a low-fouling carboxymethylated dextran (CMD) layer chemically grafted on ELISA wells. In our approach, the overnight capture antibody adsorption step found in classical ELISA was replaced by a covalent attachment step to the CMD layer completed in 15 min. As a model, the potential of our approach was highlighted using commercially available anti-human epidermal growth factor (EGF) antibodies to quantify EGF present in various samples. Of interest, the grafted CMD layer was found to be as efficient as the commonly used bovine serum albumine (BSA) to reduce non-specific adsorption, thus eliminating the need of a time-consuming BSA blocking step normally required in classical ELISA. Our results demonstrated similar specificity, affinity, and intra- and inter-assay variations regardless of the diluent used in the assay (BSA-based diluent or protein-free buffer solution) when compared to standard ELISA. Finally, accuracy and precision of the CMD-based ELISA were verified by a spike and recovery test. Dilutions of recombinant human EGF in serum from healthy human volunteers showed almost-perfect linearity and mean recovery rates ranging between 90 and 110%.
authors.affiliation: Department of Chemical Engineering, Bio-P(2) Research Unit, Ecole Polytechnique de Montréal, P.O. Box 6079, Station Centre-Ville, Montréal, Québec, Canada H3C 3A7.
authors.forename: Benoît
authors.initials: B
authors.lastname: Liberelle
authors.forename: Abderrazzak
authors.initials: A
authors.lastname: Merzouki
authors.forename: Gregory
authors.initials: G
authors.lastname: De Crescenzo
mesh_terms: D000328:Adult; D003911:Dextrans / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004815:Epidermal Growth Factor / Q000097:blood*; D005260:Female; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003911:Dextrans; D004815:Epidermal Growth Factor; C014392:carboxymethyl dextran