Description
Human CD19 (Cluster Of Differentiation 19) ELISA Kit
The Human CD19 (Cluster of Differentiation 19) ELISA Kit is a reliable and sensitive tool for detecting CD19 levels in human samples such as serum, plasma, and cell culture supernatants. CD19 is a critical protein involved in the function of B cells, playing a key role in immune response and antibody production.This kit offers high specificity and accuracy, ensuring precise and reproducible results for a variety of research applications.
CD19 is a valuable biomarker for studying immune-related conditions, including autoimmune diseases, lymphomas, and leukemia, as well as for monitoring the effectiveness of immunotherapies.Overall, the Human CD19 ELISA Kit is an essential tool for researchers seeking to better understand the role of CD19 in health and disease, and for developing novel therapeutic strategies targeting this important protein.
| Assay type: | Sandwich |
| Format: | 96T |
| Assay time: | 4.5h |
| Reactivity: | Human |
| Detection Method: | Colormetric |
| Detection Range: | 0.31-20 ng/mL |
| Sensitivity: | 0.19 ng/mL |
| Sample Volume Required Per Well: | 100µL |
| Sample Type: | Serum, plasma and other biological fluids |
| Specificity: | This kit recognizes Human CD19 in samples. No significant cross-reactivity or interference between Human CD19 and analogues was observed. |
This ELISA kit uses Sandwich-ELISA as the method. The micro ELISA plate provided in this kit has been pre-coated with an antibody specific to Human CD19. Standards or samples are added to the appropriate micro ELISA plate wells and combined with the specific antibody. Then a biotinylated detection antibody specific for Human CD19 and Avidin-Horseradish Peroxidase (HRP) conjugate are added to each micro plate well successively and incubated. Free components are washed away. The substrate solution is added to each well. Only those wells that contain Human CD19, biotinylated detection antibody and Avidin-HRP conjugate will appear blue in color. The enzyme-substrate reaction is terminated by adding Stop Solution and the color turns yellow. The optical density (OD) is measured spectrophotometrically at a wavelength of 450 nm ± 2 nm. The OD value is proportional to the concentration of Human CD19. The concentration of Human CD19 in samples can be calculated by comparing the OD of the samples to the standard curve.
| UniProt Protein Function: | Assembles with the antigen receptor of B-lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation. |
| NCBI Summary: | Lymphocytes proliferate and differentiate in response to various concentrations of different antigens. The ability of the B cell to respond in a specific, yet sensitive manner to the various antigens is achieved with the use of low-affinity antigen receptors. This gene encodes a cell surface molecule which assembles with the antigen receptor of B lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation. [provided by RefSeq, Jul 2008] |
| UniProt Code: | P15391 |
| NCBI GenInfo Identifier: | 160332376 |
| NCBI Gene ID: | 930 |
| NCBI Accession: | P15391. 6 |
| UniProt Secondary Accession: | P15391,Q96S68, Q9BRD6, A0N0P9, F5H635, |
| UniProt Related Accession: | P15391 |
| Molecular Weight: | |
| NCBI Full Name: | B-lymphocyte antigen CD19 |
| NCBI Synonym Full Names: | CD19 molecule |
| NCBI Official Symbol: | CD19 |
| NCBI Official Synonym Symbols: | B4; CVID3 |
| NCBI Protein Information: | B-lymphocyte antigen CD19 |
| UniProt Protein Name: | B-lymphocyte antigen CD19 |
| UniProt Synonym Protein Names: | B-lymphocyte surface antigen B4; Differentiation antigen CD19; T-cell surface antigen Leu-12; CD_antigen: CD19 |
| Protein Family: | B-lymphocyte antigen |
| UniProt Gene Name: | CD19 |
As the OD values of the standard curve may vary according to the conditions of the actual assay performance (e. g. operator, pipetting technique, washing technique or temperature effects), the operator should establish a standard curve for each test. Typical standard curve and data is provided below for reference only.
| Concentration (ng/mL) | O.D | Average | Corrected |
| 20 | 2.435 2.447 | 2.441 | 2.386 |
| 10 | 1.555 1.569 | 1.562 | 1.507 |
| 5 | 0.904 0.894 | 0.899 | 0.844 |
| 2.5 | 0.393 0.429 | 0.411 | 0.356 |
| 1.25 | 0.25 0.224 | 0.237 | 0.182 |
| 0.63 | 0.164 0.14 | 0.152 | 0.097 |
| 0.31 | 0.101 0.109 | 0.105 | 0.05 |
| 0 | 0.046 0.064 | 0.055 | -- |
Precision
Intra-assay Precision (Precision within an assay): 3 samples with low, mid range and high level Human CD19 were tested 20 times on one plate, respectively.
Inter-assay Precision (Precision between assays): 3 samples with low, mid range and high level Human CD19 were tested on 3 different plates, 20 replicates in each plate.
| Intra-assay Precision | Inter-assay Precision | |||||
| Sample | 1 | 2 | 3 | 1 | 2 | 3 |
| n | 20 | 20 | 20 | 20 | 20 | 20 |
| Mean (ng/mL) | 0.98 | 1.95 | 7.80 | 1.04 | 1.97 | 7.99 |
| Standard deviation | 0.06 | 0.10 | 0.24 | 0.06 | 0.11 | 0.42 |
| C V (%) | 6.12 | 5.13 | 3.08 | 5.77 | 5.58 | 5.26 |
Recovery
The recovery of Human CD19 spiked at three different levels in samples throughout the range of the assay was evaluated in various matrices.
| Sample Type | Range (%) | Average Recovery (%) |
| Serum (n=5) | 86-100 | 92 |
| EDTA plasma (n=5) | 91-107 | 98 |
| Cell culture media (n=5) | 93-106 | 100 |
Linearity
Samples were spiked with high concentrations of Human CD19 and diluted with Reference Standard & Sample Diluent to produce samples with values within the range of the assay.
| Serum (n=5) | EDTA plasma (n=5) | Cell culture media (n=5) | ||
| 1:2 | Range (%) | 98-111 | 86-97 | 90-101 |
| Average (%) | 104 | 91 | 95 | |
| 1:4 | Range (%) | 90-101 | 80-94 | 87-100 |
| Average (%) | 95 | 86 | 92 | |
| 1:8 | Range (%) | 85-101 | 86-97 | 82-95 |
| Average (%) | 92 | 92 | 88 | |
| 1:16 | Range (%) | 87-102 | 81-91 | 88-101 |
| Average (%) | 93 | 86 | 94 |
An unopened kit can be stored at 4°C for 1 month. If the kit is not used within 1 month, store the items separately according to the following conditions once the kit is received.
| Item | Specifications | Storage |
| Micro ELISA Plate(Dismountable) | 8 wells ×12 strips | -20°C, 6 months |
| Reference Standard | 2 vials | |
| Concentrated Biotinylated Detection Ab (100×) | 1 vial, 120 µL | |
| Concentrated HRP Conjugate (100×) | 1 vial, 120 µL | -20°C(shading light), 6 months |
| Reference Standard & Sample Diluent | 1 vial, 20 mL | 4°C, 6 months |
| Biotinylated Detection Ab Diluent | 1 vial, 14 mL | |
| HRP Conjugate Diluent | 1 vial, 14 mL | |
| Concentrated Wash Buffer (25×) | 1 vial, 30 mL | |
| Substrate Reagent | 1 vial, 10 mL | 4°C(shading light) |
| Stop Solution | 1 vial, 10 mL | 4°C |
| Plate Sealer | 5 pieces | |
| Product Description | 1 copy | |
| Certificate of Analysis | 1 copy |
- Set standard, test sample and control (zero) wells on the pre-coated plate and record theirpositions. It is recommended to measure each standard and sample in duplicate. Note: addall solutions to the bottom of the plate wells while avoiding contact with the well walls. Ensuresolutions do not foam when adding to the wells.
- Aliquot 100µl of standard solutions into the standard wells.
- Add 100µl of Sample / Standard dilution buffer into the control (zero) well.
- Add 100µl of properly diluted sample (serum, plasma, tissue homogenates and otherbiological fluids) into test sample wells.
- Cover the plate with the sealer provided in the kit and incubate for 90 min at 37°C.
- Aspirate the liquid from each well, do not wash. Immediately add 100µL of BiotinylatedDetection Ab working solution to each well. Cover the plate with a plate seal and gently mix. Incubate for 1 hour at 37°C.
- Aspirate or decant the solution from the plate and add 350µL of wash buffer to each welland incubate for 1-2 minutes at room temperature. Aspirate the solution from each well andclap the plate on absorbent filter paper to dry. Repeat this process 3 times. Note: a microplatewasher can be used in this step and other wash steps.
- Add 100µL of HRP Conjugate working solution to each well. Cover with a plate seal andincubate for 30 min at 37°C.
- Aspirate or decant the solution from each well. Repeat the wash process for five times asconducted in step 7.
- Add 90µL of Substrate Reagent to each well. Cover with a new plate seal and incubate forapproximately 15 min at 37°C. Protect the plate from light. Note: the reaction time can beshortened or extended according to the actual color change, but not by more than 30min.
- Add 50 µL of Stop Solution to each well. Note: Adding the stop solution should be done inthe same order as the substrate solution.
- Determine the optical density (OD value) of each well immediately with a microplate readerset at 450 nm.
