The ephrin family of proteins is encoded by Ephrin A1/EFNA1. The biggest subfamily of receptor protein-tyrosine kinases, ephrins and EPH-related receptors, have been implicated in modulating developmental events, particularly in the nervous system and erythropoiesis. Ephrins are split into two classes based on their structures and sequence relationships: the ephrin-A (EFNA) class, which are glycosylphosphatidylinositol-anchored proteins, and the ephrin-B (EFNB) class, which are transmembrane proteins. Sequence analysis showed two transcript variants that encode distinct isoforms. Cortical Senile Cataract and Low Grade Glioma are two diseases linked to EFNA1.
Product Name:
Human Ephrin A1 / EFNA1 ELISA Kit
Product Code:
HUFI01296
Size:
96 Assays
Alias:
EFNA1, Ephrin A1, EFNA1, TNF alpha induced protein 4, LERK1, EFL1, B61, ECKLG, EPLG1, TNFAIP4, Tumor necrosis factor alpha-induced protein 4, TNF alpha-induced protein 4, EPH-related receptor tyrosine kinase ligand 1, LERK-1, Immediate early response protein B61
Detection method:
Sandwich ELISA, Double Antibody
Application:
This immunoassay kit allows for the in vitro quantitative determination of Human EFNA1 concentrations in serum plasma and other biological fluids.
Sensitivity:
0.094ng/ml
Range:
0.156-10ng/ml
Storage:
4°C for 6 months
Note:
For Research Use Only
Recovery:
Matrices listed below were spiked with certain level of Human EFNA1 and the recovery rates were calculated by comparing the measured value to the expected amount of Human EFNA1 in samples.
Matrix
Recovery range(%)
Average(%)
serum(n=5)
87-100
94
EDTA plasma(n=5)
86-99
93
UFH plasma(n=5)
85-98
93
Linearity:
The linearity of the kit was assayed by testing samples spiked with appropriate concentration of Human EFNA1 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)
85-104%
88-105%
87-102%
EDTA plasma(n=5)
86-101%
85-97%
86-101%
UFH plasma(n=5)
80-100%
82-100%
85-99%
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
Cell surface GPI-bound ligand for Eph receptors, a family of receptor tyrosine kinases which are crucial for migration, repulsion and adhesion during neuronal, vascular and epithelial development. Binds promiscuously Eph receptors residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. Plays an important role in angiogenesis and tumor neovascularization. The recruitment of VAV2, VAV3 and PI3-kinase p85 subunit by phosphorylated EPHA2 is critical for EFNA1-induced RAC1 GTPase activation and vascular endothelial cell migration and assembly. Exerts anti-oncogenic effects in tumor cells through activation and down-regulation of EPHA2. Activates EPHA2 by inducing tyrosine phosphorylation which leads to its internalization and degradation. Acts as a negative regulator in the tumorigenesis of gliomas by down-regulating EPHA2 and FAK. Can evoke collapse of embryonic neuronal growth cone and regulates dendritic spine morphogenesis.
NCBI Summary:
This gene encodes a member of the ephrin (EPH) family. The ephrins and EPH-related receptors comprise the largest subfamily of receptor protein-tyrosine kinases and have been implicated in mediating developmental events, especially in the nervous system and in erythropoiesis. Based on their structures and sequence relationships, ephrins are divided into the ephrin-A (EFNA) class, which are anchored to the membrane by a glycosylphosphatidylinositol linkage, and the ephrin-B (EFNB) class, which are transmembrane proteins. This gene encodes an EFNA class ephrin which binds to the EPHA2, EPHA4, EPHA5, EPHA6, and EPHA7 receptors. Two transcript variants that encode different isoforms were identified through sequence analysis. [provided by RefSeq, Jul 2008]
*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.
