This assay has high sensitivity and excellent specificity for detection of Fibroblast Growth Factor 21 (FGF21). No significant cross-reactivity or interference between Fibroblast Growth Factor 21 (FGF21) and analogues was observed.
Pre-coated, ready to use 96-well strip plate
Plate sealer for 96 wells
Assay Diluent A
Assay Diluent B
Detection Reagent A
Detection Reagent B
Wash Buffer (30 × concentrate)
Material not included
Microplate reader with 450 nm filter.
Precision single or multi-channel pipettes and disposable tips.
Eppendorf Tubes for diluting samples.
Deionized or distilled water.
Absorbent paper for blotting the microtiter plate.
Limited by the current condition and scientific technology, we cannot completely conduct the comprehensive identification and analysis on the raw material provided by suppliers. So there might be some qualitative and technical risks to use the kit.
The final experimental results will be closely related to validity of the products, operation skills of the end users and the experimental environments. Please make sure that sufficient samples are available.
Kits from different batches may be a little different in detection range, sensitivity and color developing time.
Do not mix or substitute reagents from one kit lot to another. Use only the reagents supplied by manufacturer.
Protect all reagents from strong light during storage and incubation. All the bottle caps of reagents should be covered tightly to prevent the evaporation and contamination of microorganism.
There may be some foggy substance in the wells when the plate is opened at the first time. It will not have any effect on the final assay results. Do not remove microtiter plate from the storage bag until needed.
Wrong operations during the reagents preparation and loading, as well as incorrect parameter setting for the plate reader may lead to incorrect results. A microplate plate reader with a bandwidth of 10nm or less and an optical density range of 0-3 O.D. or greater at 450 ± 10nm wavelength is acceptable for use in absorbance measurement. Please read the instruction carefully and adjust the instrument prior to the experiment.
Even the same operator might get different results in two separate experiments. In order to get better reproducible results, the operation of every step in the assay should be controlled. Furthermore, a preliminary experiment before assay for each batch is recommended.
Each kit has been strictly passed Q.C test. However, results from end users might be inconsistent with our in-house data due to some unexpected transportation conditions or different lab equipments. Intra-assay variance among kits from different batches might arise from above factors, too.
Kits from different manufacturers for the same item might produce different results, since we have not compared our products with other manufacturers.
Information on standard material: The standard might be recombinant protein or natural protein, that will depend on the specific kit. Moreover, the expression system is E.coli or yeast or mammal cell. There is 0.05% proclin 300 in the standard as preservative.
Information on reagents: The stop solution used in the kit is sulfuric acid with concentration of 1 mol/L. And the wash solution is TBS. The standard diluent contains 0.02 % sodium azide, assay diluent A and assay diluent B contain 0.01% sodium azide. Some kits can contain is BSA in them.
Information on antibodies: The provided antibodies and their host vary in different kits.
This assay employs the competitive inhibition enzyme immunoassay technique. A monoclonal antibody specific to Fibroblast Growth Factor 21 (FGF21) has been pre-coated onto a microplate. A competitive inhibition reaction is launched between biotin labeled Fibroblast Growth Factor 21 (FGF21) and unlabeled Fibroblast Growth Factor 21 (FGF21) (Standards or samples) with the pre-coated antibody specific to Fibroblast Growth Factor 21 (FGF21). After incubation the unbound conjugate is washed off. Next, avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. The amount of bound HRP conjugate is reverse proportional to the concentration of Fibroblast Growth Factor 21 (FGF21) in the sample. After addition of the substrate solution, the intensity of color developed is reverse proportional to the concentration of Fibroblast Growth Factor 21 (FGF21) in the sample.
We are only responsible for the kit itself, but not for the samples consumed during the assay. The user should calculate the possible amount of the samples used in the whole test. Please reserve sufficient samples in advance.
Please predict the concentration before assaying. If values for these are not within the range of the standard curve, users must determine the optimal sample dilutions for their particular experiments. Sample should be diluted by 0.01mol/L PBS(PH=7.0-7.2).
If the samples are not indicated in the manual, a preliminary experiment to determine the validity of the kit is necessary.
Tissue or cell extraction samples prepared by chemical lysis buffer may cause unexpected ELISA results due to the impacts from certain chemicals.
Due to the possibility of mismatching between antigen from other origin and antibody used in our kits (e.g.antibody targets conformational epitope rather than linear epitope), some native or recombinant proteins from other manufacturers may not be recognized by our products.
Influenced by the factors including cell viability, cell number or sampling time, samples from cell culture supernatant may not be detected by the kit.
Fresh samples without long time storage is recommended for the test. Otherwise, protein degradation and denaturalization may occur in those samples and finally lead to wrong results.
Prepare all reagents, samples and standards,
Add 50μL standard or sample to each well. And then add 50μL prepared Detection Reagent A immediately. Shake and mix. Incubate 1 hour at 37 °C,
Aspirate and wash 3 times,
Add 100μL prepared Detection Reagent B. Incubate 30 minutes at 37 °C,
Aspirate and wash 5 times,
Add 90μL Substrate Solution. Incubate 10-20 minutes at 37 °C,
Add 50μL Stop Solution. Read at 450 nm immediately.
Intra-assay Precision (Precision within an assay): 3 samples with low, middle and high level Fibroblast Growth Factor 21 (FGF21) were tested 20 times on one plate, respectively. Inter-assay Precision (Precision between assays): 3 samples with low, middle and high level Fibroblast Growth Factor 21 (FGF21) were tested on 3 different plates, 8 replicates in each plate. CV(%) = SD/meanX100 Intra-Assay: CV<10% Inter-Assay: CV<12%
The Stop Solution suggested for use with this kit is an acid solution. Wear eye, hand, face, and clothing protection when using this material.
The stability of kit is determined by the loss rate of activity. The loss rate of this kit is less than 5 % within the expiration date under appropriate storage condition. To minimize extra influence on the performance, operation procedures and lab conditions, especially room temperature, air humidity, incubator temperature should be strictly controlled. It is also strongly suggested that the whole assay is performed by the same operator from the beginning to the end.
For unopened kit: All the reagents should be kept according to the labels on vials. The Standard, Detection Reagent A, Detection Reagent B and the 96-well strip plate should be stored at -20°C upon receipt while the others should be at 4°C.
For opened kit: When the kit is opened, the remaining reagents still need to be stored according to the above storage condition. Besides, please return the unused wells to the foil pouch containing the desiccant pack, and reseal along entire edge of zip-seal. Note: It is highly recommended to use the remaining reagents within 1 month provided this is within the expiration date of the kit.
For ELISA kit, 1 day storage at 37°C can be considered as 2 months at 4°C, which means 3 days at 37°C equaling 6 months at 4°C.