Human IL-21 ELISA (Enzyme-Linked Immunosorbent Assay) Kit is an in vitro enzyme-linked immunosorbent assay kit used for quantitative determination of IL-21 in serum, plasma, and cell culture supernatants. Specific anti-IL-21 antibodies are pre-coated onto high-affinity enzyme plates. Standards and samples are added to the wells of the enzyme plate, and after incubation, IL-21 present in the sample binds to the solid-phase antibody. After washing to remove unbound substances, a detection antibody is added for binding and incubated, followed by washing, and then the enzyme complex (Streptavidin-HRP) is added for binding and incubated. After washing, a colorimetric substrateTMB is added for color development, avoiding light. The intensity of the color reaction is proportional to the concentration of IL-21 in the sample. The reaction is terminated by adding a stop solution, and the absorbance is measured at 450 nm wavelength (with a reference wavelength of 570 - 630 nm).
Human Interleukin-21 (IL-21) is a type I cytokine that regulates the functions of T cells, B cells, NK cells, and myeloid cells. IL-21 is produced by activated follicular helper T cells (Tfh), Th17 cells, and NKT cells. IL-21 derived from Tfh cells plays a crucial role in the development of humoral immunity through its autocrine effects on Tfh cells and paracrine effects on immunoglobulin maturation, plasma cell differentiation, and memory B cells. Mature human IL-21 consists of 133 amino acids and shares 63% and 61% sequence identity with mouse and rat IL-21, respectively. IL-21 is closely associated with clinical conditions such as cancer immunotherapy, viral infections, and allergies. It also inhibits skin hypersensitivity reactions by limiting the production of allergen-specific IgE and degranulation of mast cells.
Specification
|
Item Number
|
P162019S / P162019E |
| Specification |
48 T / 96 T |
| Detection Range |
15.63-1000 pg/mL |
| Detection Method |
Sandwich ELISA |
| Detection Species |
Human |
| Detection Time |
4.5 hours |
| Sensitivity |
8.16 pg/mL |
| Dilution Linearity |
81 - 117% |
| Recovery Rate |
76 - 121% |
| Intra-assay Variability |
3.3% |
| Intra-assay Variability |
5.0% |
Components
| Component Number |
Component Name |
Storage Temperature |
P162019S |
P162019E |
| P162019-A |
ELISA Plate |
2~8℃ |
48 T |
96 T |
| P162019-B |
Standard |
2~8℃ |
1 tube |
2 tubes |
| P162019-C |
Detection Antibody |
2~8℃ |
120 μL |
240 μL |
| P162019-D |
Enzyme Conjugate |
2~8℃(Avoid Light) |
30 μL |
60 μL |
| P162019-E |
5x Dilution Buffer |
2~8℃ |
8 mL |
15 mL |
| P162019-F |
20x Wash Buffer |
2~8℃ |
25 mL |
50 mL |
| P162019-G |
Substrate Solution |
2~8℃(Avoid Light) |
8 mL |
15 mL |
| P162019-H |
Stop Solution |
Room Temperature |
5 mL |
10 mL |
| P162019-I |
Plate Sealers |
Room Temperature |
3 pieces |
5 pieces |
Storage
The assay kit can be stored at 2~8℃. Alternatively, the reagents can be stored according to the storage conditions provided in the component information to avoid contamination and repeated freeze-thaw cycles. Diluted working solutions should be used immediately and not reused. The shelf life is 1 year.
Table 1 Reagent Storage Table After Initial Use
| Material Name
|
Storage Conditions |
| Plate |
Unused strips can be returned to the aluminum foil bag, tightly sealed, and stored at 2~8°C to avoid moisture absorption.
|
| Standard |
Use within 48 hours after dissolution, store at 2~8°C to avoid contamination.
|
| Detection Antibody |
Use within 48 hours after dilution, store at 2~8°C to avoid contamination. |
| Enzyme conjugate |
Use within 48 hours after dilution, store at 2~8°C to avoid contamination. |
| 5×Dilution Buffer |
Store at 2~8°C for 1 month, avoiding contamination. |
| 20×Wash Buffer |
Store at 2~8°C for 1 month, avoiding contamination. |
| Substrate solution |
Store at 2~8°C for 1 month, avoiding light exposure.
|
| Stop Solution |
Can be stored at room temperature. |
| Plate Sealers |
Can be stored at room temperature. |
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