Highly Sensitive and Accurate Analyte Quantification Every Time
The enzyme-linked immunosorbent assay (ELISA) is a quantitative, highly sensitive assay for the detection of analytes present in biological samples such as serum, plasma and cell culture supernatants. This widely used immunoassay can be used to evaluate cell activation and/or differentiation through the detection and accurate quantification of substances such as cytokines, hematological factors, hormones, peptides, and immunoglobulins.
Why Use Our ELISA Kits?
- Highly specific antibodies detect analytes in the low pg/mL range.
- Standards are calibrated against international references.
- Low intra- and inter-assay variability ensures consistency within and between experiments.
- Complete, ready-to-use kits include pre-coated 96-well strip microplates for a selection of human and mouse analytes.
Take the guesswork out of cell analysis and evaluate your cells using ELISA Kits that are compatible with your workflow. Choose from a selection of highly-sensitive ELISA kits with low intra- and inter-assay variability for accurate, precise, and consistent analyte quantification.
Complete, ready-to-use ELISA kits are conveniently packaged with all the required standards, substrates, and solutions — as well as pre-coated 96-well strip microplates — to reduce assay time and variability. Alternatively, ELISA antibody pair kits offer the flexibility to customize your assay and come with optimized and matched quantities of capture and detection antibodies, plus an analyte standard. In both types of ELISA kit, included standards are calibrated against international references for accurate results.
Figure 1. Procedure for the Detection of Cytokines Using Complete, Ready-to-Use ELISA Kits
How It Works
The sandwich ELISA protocol involves immobilizing an antibody against the analyte of interest to a solid surface, typically a 96-well polystyrene microplate. A test sample is then added to the microplate and the target analyte, if present, binds to the immobilized antibody. Unbound proteins are then washed away, leaving only the analyte of interest. The bound target is then recognized and bound by a second analyte-specific antibody, which is linked (either directly or via Biotin-Streptavidin) to a detection enzyme. Detection and quantification of the target analyte is accomplished by adding a substrate for the linked enzyme and measuring the color change reaction. The most commonly used enzymes for ELISA are horseradish peroxidase (HRP) and alkaline phosphatase (AP).
Complete ELISA Kits Include:
- 96-well strip microplate(s) pre-coated with capture antibody
- Biotinylated detection antibody
- Streptavidin-HRP conjugate
- Analyte standard(s)
- Assay buffer and diluent(s)
- Wash buffer
- TMB substrate solution
- Stop solution
- Adhesive plate covers
ELISA Antibody Pair Kits Include:
- Capture antibody
- Biotinylated detection antibody and Streptavidin-ALP conjugate OR ALP-conjugated detection antibody
- Analyte standard
Figure 2. ELISA Kits Measure IL-2, IL-4 and IFN- Secreted-γ Secreted by Activated Human T cells
T cells were isolated from human apheresed blood using EasySep™ Human T Cell Isolation Kit. Isolated T cells were cultured in either: RPMI Medium supplemented with 10% FBS, with or without 40 ng/mL PMA and 1 ug/mL Ionomycin for 24 hours, or ImmunoCult™-XF T Cell Expansion Medium, with or without ImmunoCult™ Human CD3/CD28 T Cell Activator for 48 hours. Supernatants were collected from the activated T cell cultures, and concentrations of secreted cytokines were determined using Human IL-2 ELISA Kit, Human IL-4 ELISA Kit and Human IFN-γ ELISA Kit. Activation by either PMA and Ionomycin or ImmunoCult™ Human CD3/CD28 T Cell Activator led to increased secretion of all 3 cytokines compared to unstimulated control cultures.
Figure 3. ELISA Kits Measure IL-12 (p70) and IL-23 Secretion by Activated Dendritic Cells (DCs)
Monocytes were isolated from human PBMCs using EasySep™ Human Monocyte Isolation Kit. Cells were cultured for 6 days in RPMI Medium supplemented with 10% FBS (non-differentiated control) or the same media with the addition of 500 U/mL Human Recombinant IL-4 and 1000 U/mL Human Recombinant GM-CSF to induce differentiation to dendritic cells (DCs). DCs were then cultured for 2 days in RPMI Medium supplemented with 10% FBS (non-activated control) or the same medium with the addition of 10 ng/mL LPS and 500 U/mL Human Recombinant IFN-γ. Supernatants were collected from the cultures on day 8, and concentrations of secreted cytokines were determined using Human IL-12 (p70) ELISA Kit and Human IL-23 ELISA Kit. Both cytokines were highly expressed by the activated cells compared to non-activated control cultures.
Figure 4. STEMCELL ELISA Kits Show a Wider Linear Range Compared to Competitors
A wider range of linearity in STEMCELL ELISA kits is demonstrated by the standard curve of the Human IL-10 ELISA Kit compared to that of Competitors 1 - 4. The Human IL-10 ELISA Kit shows the broadest range of linearity resulting in the widest working range in which IL-10 concentrations can be accurately and precisely measured.
Figure 5. STEMCELL ELISA Kits Show Higher Sensitivity Compared to Competitors
High sensitivity in STEMCELL ELISA kits is demonstrated by lower limit of detection (LOD) values for the Human IL-10 and Mouse TNF-alpha ELISA Kits compared to Competitors 1 - 4. Limit of detection was determined by measuring absorbance values from n=18 replicates of 0 pg/mL standard, determining the mean value and standard deviation (SD), and calculating the LOD concentration as the mean + 3 SD interpolated from the standard curve.
Figure 6. STEMCELL ELISA Kits Show Higher Precision Compared to Competitors
High precision in STEMCELL ELISA kits is demonstrated by lower coefficient of variation (CV) for the Human IL-10 and Mouse TNF-alpha ELISA Kit compared to Competitors 1 - 4. Intra-assay precision was determined by measuring n=15 replicates of a 30 pg/mL of human IL-10 or 100 pg/mL of mouse TNF-alpha sample, determining the mean value and standard deviation (SD), and calculating the coefficient of variation as SD/mean.