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Our strict manufacturing and quality control standards allow us to offer the highest levels of performance and consistency with each Elisa kit you run. CUSABIO Elisa kits provide our customers with the linearity range, linearity, Lower Limit of Detection, precision, recovery, stability and natural samples detection that they expect due to strict validation testing. This testing includes:
Through the linear range, we can calculate the actual testing sample value. Customers can download the software here to draw the standard curve: https://www.cusabio.com/m-225.html. Here is the standard curve for CSB-E07270h (Human adiponectin, ADP ELISA Kit). Duplicated wells were run for the standards.
| ng/ml | OD1 | OD2 | Average | Corrected |
|---|---|---|---|---|
| 100 | 2.839 | 2.897 | 2.868 | 2.718 |
| 50 | 1.968 | 1.974 | 1.971 | 1.821 |
| 25 | 1.144 | 1.192 | 1.168 | 1.018 |
| 12.5 | 0.709 | 0.733 | 0.721 | 0.571 |
| 6.25 | 0.433 | 0.450 | 0.441 | 0.291 |
| 3.125 | 0.303 | 0.301 | 0.302 | 0.152 |
| 1.562 | 0.242 | 0.223 | 0.233 | 0.083 |
| 0 | 0.149 | 0.151 | 0.150 |
Linearity is the test index of experimental accuracy and specificity.
To assess the linearity of the assay, samples were spiked with high concentrations of analyte in various matrices and diluted with the Sample Diluent to produce samples with values within the dynamic range of the assay. The results are expressed as a percent observed.
Take CSB-E07270h (Human adiponectin, ADP ELISA Kit) as an example:
Serum samples were diluted under 1：100、1：200、1：400、1：800.
Cell Culture Supernates were diluted under 1：1、1：2、1：4、1：8.
The tested values are between 80-120% and show good linearity.
| Sample | Serum(n=4) | |
|---|---|---|
| 1:100 | Average( %) | 91 |
| Range ( %) | 85-97 | |
| 1:200 | Average( %) | 97 |
| Range ( %) | 91-103 | |
| 1:400 | Average( %) | 93 |
| Range ( %) | 85-95 | |
| 1:800 | Average( %) | 95 |
| Range ( %) | 90-100 |
| Sample | Cell Culture Supernates(n=4) | |
|---|---|---|
| 1:1 | Average( %) | 97 |
| Range ( %) | 80-100 | |
| 1:2 | Average( %) | 95 |
| Range ( %) | 91-110 | |
| 1:4 | Average( %) | 90 |
| Range ( %) | 85-95 | |
| 1:8 | Average( %) | 96 |
| Range ( %) | 90-100 |
The limit of detection is the test index of sensitivity. The lower detection limit, the higher the sensitivity.
Precision is the test index of repeatability. It is measured as a coefficient of variation (CV) from the mean value. The higher the precision, the better the repeatability. Two types of precision should be considered: intra-assay precision and inter-assay precision.
Intra-assay precision: Intra-assay precision is the reproducibility between wells within an assay. Three samples of known concentration were tested twenty times on one plate to assess the precision of CSB-E07270h (Human adiponectin, ADP ELISA Kit): CV%<8%.
Inter-assay precision: Inter-assay precision is the reproducibility between assays. Three samples of known concentration were tested in twenty assays to assess the precision of CSB-E07270h (Human adiponectin, ADP ELISA Kit): CV%<10%.
| Intra-Assay Precision | Inter-Assay Precision | |||||
|---|---|---|---|---|---|---|
| Sample | 1 | 2 | 3 | 1 | 2 | 3 |
| n | 20 | 20 | 20 | 20 | 20 | 20 |
| Mean(ng/ml) | 13.215 | 12.894 | 13.438 | 12.897 | 13.109 | 12.963 |
| SD | 0.63 | 0.37 | 0.53 | 1.10 | 0.81 | 1.00 |
| CV(%) | 4.75 | 2.847 | 3.931 | 8.562 | 6.145 | 7.741 |
Recovery is the test index of experimental accuracy and specificity. It reflects the loss degree of analyte in the sample analysis process. The higher the recovery rate, the higher the accuracy.
The recovery of analyte spiked to levels throughout the range of the assay in various matrices was evaluated. Samples were diluted prior to assay as directed in the Sample Preparation section. Here is the recovery rate of CSB-E07270h (Human adiponectin, ADP ELISA Kit).
| Sample Type | Average(%) | Range(%) |
|---|---|---|
| Serum (n=5) | 95 | 89-98 |
| EDTA plasma (n=4) | 97 | 90-100 |
The better the stability, the longer the storage time. The main raw materials and the assay plate of Cusabio Elisa kit were tested with thermal damage under 37C for 7 days and then compared with the raw materials stored under 4C. After 7 days, OD values≦30%, which is qualified.
Specificity is the crucial index for ELISA kit. CUSABIO selects raw materials with high specificity to ensure ELISA Kit's excellent specificity, analyzes the cross-reactivity and interference to confirm that only target analytes can be recognized and detected.
Natural samples detection is crucial for the use of ELISA Kit. Cusabio Elisa kits can detect natural samples, and the sample value can be as the reference for the user. For CSB-E07270h (Human adiponectin, ADP ELISA Kit), we tested serum and plasma samples under 1:500 dilution before, and the test value is S3-S5.
