Mouse IL21(Interleukin 21) ELISA Kit
Specification: Price:
48 T $320.00
96 T $458.00


Product name: Mouse IL21(Interleukin 21) ELISA Kit
Reactivity: Mouse
Alternative Names: IL-21;Za11
Assay Type: Sandwich
Sensitivity: 5.9 pg/mL
Standard: 1000 pg/mL
Range: 15.63-1000 pg/mL
Sample Type: serum, plasma, tissue homogenates, cell lysates, cell culture supernates and other biological fluids
Assay Length: 3.5h
Research Area: Cytokine;Infection immunity;
Test principle: The test principle applied in this kit is Sandwich enzyme immunoassay. The microtiter plate provided in this kit has been pre-coated with an antibody specific to Interleukin 21(IL21). Standards or samples are added to the appropriate microtiter plate wells then with a biotin-conjugated antibody specific to Interleukin 21(IL21). Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After TMB substrate solution is added, only those wells that contain Interleukin 21(IL21), biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450nm ± 10nm. The concentration of Interleukin 21(IL21) in the samples is then determined by comparing the OD of the samples to the standard curve.

Standard curve

Concentration (ng/mL) OD Corrected OD
1000.00 2.045 1.952
500.00 1.577 1.484
250.00 1.197 1.104
125.00 0.921 0.828
62.50 0.597 0.504
31.25 0.312 0.219
15.63 0.223 0.130
0.00 0.093 0.000


Intra-assay Precision (Precision within an assay):CV%<8%

Three samples of known concentration were tested twenty times on one plate to assess intra-assay precision.

Inter-assay Precision (Precision between assays):CV%<10%

Three samples of known concentration were tested in forty separate assays to assess inter-assay precision.


Matrices listed below were spiked with certain level of recombinant IL21 and the recovery rates were calculated by comparing the measured value to the expected amount of IL21 in samples.
Matrix Recovery range Average
serum(n=5) 80-96% 88%
EDTA plasma(n=5) 82-98% 90%
Heparin plasma(n=5) 84-98% 91%


The linearity of the kit was assayed by testing samples spiked with appropriate concentration of IL21 and their serial dilutions. The results were demonstrated by the percentage of calculated concentration to the expected.
Matrix 1:2 1:4 1:8 1:16
serum(n=5) 95-102% 83-96% 97-105% 85-97%
EDTA plasma(n=5) 88-97% 96-105% 81-96% 93-107%
Heparin plasma(n=5) 85-94% 87-96% 92-101% 82-95%