title: Sequential ELISA for cytokine levels in limited volumes of biological fluids.
abstract: We have developed an enzyme-linked immunosorbent assay (ELISA) for the sequential analysis of multiple cytokines in limited volumes of biological fluids, including gingival crevicular fluid (GCF) and fibroblast culture supernatants (CS). GCF and CS samples were assayed for multiple cytokines, including IL-1 beta, IL-6, IL-8, GM-CSF and IFN gamma. Immulon 3 microplates were coated with a monoclonal antibody, and a rabbit polyclonal antibody was used to detect the cytokine of interest. Biological samples (200 microL) were added to an anti-IL-1 beta-coated plate and incubated, and 175 microL of each sample were replicate transferred to an anti-IFN gamma-coated plate containing 25 microL/well of diluent. This was repeated in an identical fashion with sequential replicate transfers to an anti-IL-8-coated and finally an anti-IL-6-coated plate. The cytokine standard was a pooled combination of the recombinant human cytokines that were included in the sequence. The plates were developed using an alkaline phosphatase-conjugated goat anti-rabbit IgG and NPP as the substrate. Individual ELISAs ranged in sensitivity from 30 to 2 pg/0.2 mL, with cross-reactivity between these cytokines of < 1%. Additionally, when the same samples were tested in the sequence ELISA vs. the individual ELISA, there was > 85% correlation between the two assays.
authors.affiliation: University of Texas Health Science Center at San Antonio, San Antonio, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Steffen
authors.forename: J L
authors.initials: JL
authors.lastname: Ebersole
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000737:chemistry*; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000737:chemistry; D016207:Cytokines / Q000032:analysis* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005347:Fibroblasts / Q000378:metabolism; D005881:Gingiva / Q000166:cytology; D005883:Gingival Crevicular Fluid / Q000737:chemistry; D006041:Goats; D006801:Humans; D008832:Microchemistry; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D017077:Culture Media, Conditioned; D016207:Cytokines