Human Interleukin-7 ELISA Kit

From Antibodies.com, this Sandwich ELISA is designed for the in vitro quantitative determination of human Interleukin-7 in serum, plasma and cell culture supernatant. The kit applies a quantitative sandwich immunoassay format in which a monoclonal antibody specific to IL-7 is pre-coated on the microplate. Standards or samples are added together with a biotin-conjugated polyclonal antibody preparation specific for IL-7, so that IL-7 present in the sample becomes immobilised and then "sandwiched" by the biotin conjugate. After thorough washing, Avidin conjugated to Horseradish Peroxidase (HRP) is added, followed by a TMB (3,3′,5,5′-tetramethylbenzidine) substrate solution. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the colour change is measured spectrophotometrically at a wavelength of 450 nm ± 2 nm.

Two calibration diluents are supplied: Calibrator Diluent I for serum/plasma testing and Calibrator Diluent II for cell culture supernatant testing. The provided standard is diluted 2-fold with the appropriate Calibrator Diluent and assayed alongside the samples, allowing the operator to produce a standard curve of Optical Density (O.D.) versus IL-7 concentration (pg/mL). The platform is a pre-coated microplate of 12 × 8 well strips with colorimetric detection; the assay time is 3h 30m and the reagents are shipped and stored at 4°C.

The assay detects both natural and recombinant human IL-7 and has shown no cross-reactivity with other cytokines tested. Manufacturer-reported performance figures are a sensitivity of < 1 pg/ml and an assay range of 1.5–50 pg/ml.