The Human Complement C4b ELISA Kit is a highly sensitive and specific assay designed for the precise measurement of complement C4b levels in human samples such as serum, plasma, and cell culture supernatants. This kit provides accurate and reproducible results, making it an ideal tool for a variety of research applications.Complement C4b is a key component of the complement system, which plays a crucial role in the immune response by promoting inflammation and opsonization. Dysregulation of complement activation has been implicated in various diseases, including autoimmune disorders, infections, and inflammatory conditions.
Therefore, monitoring complement C4b levels can provide valuable insights into the underlying mechanisms of these diseases and facilitate the development of potential therapeutic interventions.The Human Complement C4b ELISA Kit is a valuable resource for researchers studying the complement system and its involvement in disease pathology. With its high performance and reliability, this kit enables accurate quantification of complement C4b levels, advancing our understanding of the immune response and opening new avenues for targeted treatment strategies.
This immunoassay kit allows for the in vitro quantitative determination of Human C4B concentrations in serum plasma and other biological fluids.
Sensitivity:
2.813ng/ml
Range:
4.688-300ng/ml
Storage:
4°C for 6 months
Note:
For Research Use Only
Recovery:
Matrices listed below were spiked with certain level of Human C4B and the recovery rates were calculated by comparing the measured value to the expected amount of Human C4B in samples.
Matrix
Recovery range(%)
Average(%)
serum(n=5)
86-105
98
EDTA plasma(n=5)
88-96
92
UFH plasma(n=5)
87-95
91
Linearity:
The linearity of the kit was assayed by testing samples spiked with appropriate concentration of Human C4B and their serial dilutions. The results were demonstrated by the percentage of calculated concentration to the expected.
Sample
1:2
1:4
1:8
serum(n=5)
91-102%
89-103%
88-101%
EDTA plasma(n=5)
89-99%
88-99%
94-97%
UFH plasma(n=5)
83-99%
83-97%
84-96%
CV(%):
Intra-Assay: CV<8% Inter-Assay: CV<10%
Component
Quantity
Storage
ELISA Microplate (Dismountable)
8×12 strips
4°C for 6 months
Lyophilized Standard
2
4°C/-20°C
Sample/Standard Dilution Buffer
20ml
4°C
Biotin-labeled Antibody(Concentrated)
120ul
4°C (Protect from light)
Antibody Dilution Buffer
10ml
4°C
HRP-Streptavidin Conjugate(SABC)
120ul
4°C (Protect from light)
SABC Dilution Buffer
10ml
4°C
TMB Substrate
10ml
4°C (Protect from light)
Stop Solution
10ml
4°C
Wash Buffer(25X)
30ml
4°C
Plate Sealer
5
-
Other materials and equipment required:
Microplate reader with 450 nm wavelength filter
Multichannel Pipette, Pipette, microcentrifuge tubes and disposable pipette tips
Non-enzymatic component of C3 and C5 convertases and thus essential for the propagation of the classical complement pathway. Covalently binds to immunoglobulins and immune complexes and enhances the solubilization of immune aggregates and the clearance of IC through CR1 on erythrocytes. C4A isotype is responsible for effective binding to form amide bonds with immune aggregates or protein antigens, while C4B isotype catalyzes the transacylation of the thioester carbonyl group to form ester bonds with carbohydrate antigens.
NCBI Summary:
This gene encodes the basic form of complement factor 4, part of the classical activation pathway. The protein is expressed as a single chain precursor which is proteolytically cleaved into a trimer of alpha, beta, and gamma chains prior to secretion. The trimer provides a surface for interaction between the antigen-antibody complex and other complement components. The alpha chain may be cleaved to release C4 anaphylatoxin, a mediator of local inflammation. Deficiency of this protein is associated with systemic lupus erythematosus. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. Varying haplotypes of this gene cluster exist, such that individuals may have 1, 2, or 3 copies of this gene. In addition, this gene exists as a long form and a short form due to the presence or absence of a 6.4 kb endogenous HERV-K retrovirus in intron 9. [provided by RefSeq, Jul 2008]
Acidic complement C4; C3 and PZP-like alpha-2-macroglobulin domain-containing protein 2
Protein Family:
Complement C4
UniProt Gene Name:
C4AÂ Â
*Note: Protocols are specific to each batch/lot. For the correct instructions please follow the protocol included in your kit.
Before adding to wells, equilibrate the SABC working solution and TMB substrate for at least 30 min at 37°C. When diluting samples and reagents, they must be mixed completely and evenly. It is recommended to plot a standard curve for each test.
Step
Protocol
1.
Set standard, test sample and control (zero) wells on the pre-coated plate respectively, and then, record their positions. It is recommended to measure each standard and sample in duplicate. Wash plate 2 times before adding standard, sample and control (zero) wells!
2.
Aliquot 0.1ml standard solutions into the standard wells.
3.
Add 0.1 ml of Sample / Standard dilution buffer into the control (zero) well.
4.
Add 0.1 ml of properly diluted sample ( Human serum, plasma, tissue homogenates and other biological fluids.) into test sample wells.
5.
Seal the plate with a cover and incubate at 37 °C for 90 min.
6.
Remove the cover and discard the plate content, clap the plate on the absorbent filter papers or other absorbent material. Do NOT let the wells completely dry at any time. Wash plate X2.
7.
Add 0.1 ml of Biotin- detection antibody working solution into the above wells (standard, test sample & zero wells). Add the solution at the bottom of each well without touching the side wall.
8.
Seal the plate with a cover and incubate at 37°C for 60 min.
9.
Remove the cover, and wash plate 3 times with Wash buffer. Let wash buffer rest in wells for 1 min between each wash.
10.
Add 0.1 ml of SABC working solution into each well, cover the plate and incubate at 37°C for 30 min.
11.
Remove the cover and wash plate 5 times with Wash buffer, and each time let the wash buffer stay in the wells for 1-2 min.
12.
Add 90 µl of TMB substrate into each well, cover the plate and incubate at 37°C in dark within 10-20 min. (Note: This incubation time is for reference use only, the optimal time should be determined by end user.) And the shades of blue can be seen in the first 3-4 wells (with most concentrated standard solutions), the other wells show no obvious color.
13.
Add 50 µl of Stop solution into each well and mix thoroughly. The color changes into yellow immediately.
14.
Read the O.D. absorbance at 450 nm in a microplate reader immediately after adding the stop solution.
When carrying out an ELISA assay it is important to prepare your samples in order to achieve the best possible results. Below we have a list of procedures for the preparation of samples for different sample types.
Sample Type
Protocol
Serum
If using serum separator tubes, allow samples to clot for 30 minutes at room temperature. Centrifuge for 10 minutes at 1,000x g. Collect the serum fraction and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles.
If serum separator tubes are not being used, allow samples to clot overnight at 2-8°C. Centrifuge for 10 minutes at 1,000x g. Remove serum and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles.
Plasma
Collect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples at 4°C for 15 mins at 1000 × g within 30 mins of collection. Collect the plasma fraction and assay promptly or aliquot and store the samples at -80°C. Avoid multiple freeze-thaw cycles. Note: Over haemolysed samples are not suitable for use with this kit.
Urine & Cerebrospinal Fluid
Collect the urine (mid-stream) in a sterile container, centrifuge for 20 mins at 2000-3000 rpm. Remove supernatant and assay immediately. If any precipitation is detected, repeat the centrifugation step. A similar protocol can be used for cerebrospinal fluid.
Cell culture supernatant
Collect the cell culture media by pipette, followed by centrifugation at 4°C for 20 mins at 1500 rpm. Collect the clear supernatant and assay immediately.
Cell lysates
Solubilize cells in lysis buffer and allow to sit on ice for 30 minutes. Centrifuge tubes at 14,000 x g for 5 minutes to remove insoluble material. Aliquot the supernatant into a new tube and discard the remaining whole cell extract. Quantify total protein concentration using a total protein assay. Assay immediately or aliquot and store at ≤ -20 °C.
Tissue homogenates
The preparation of tissue homogenates will vary depending upon tissue type. Rinse tissue with 1X PBS to remove excess blood & homogenize in 20ml of 1X PBS (including protease inhibitors) and store overnight at ≤ -20°C. Two freeze-thaw cycles are required to break the cell membranes. To further disrupt the cell membranes you can sonicate the samples. Centrifuge homogenates for 5 mins at 5000xg. Remove the supernatant and assay immediately or aliquot and store at -20°C or -80°C.
Tissue lysates
Rinse tissue with PBS, cut into 1-2 mm pieces, and homogenize with a tissue homogenizer in PBS. Add an equal volume of RIPA buffer containing protease inhibitors and lyse tissues at room temperature for 30 minutes with gentle agitation. Centrifuge to remove debris. Quantify total protein concentration using a total protein assay. Assay immediately or aliquot and store at ≤ -20 °C.
Breast Milk
Collect milk samples and centrifuge at 10,000 x g for 60 min at 4°C. Aliquot the supernatant and assay. For long term use, store samples at -80°C. Minimize freeze/thaw cycles.
