Human Forkhead Box Protein P3 (FOXP3) ELISA Kit

Principle of the Assay

The test principle applied in this kit is Sandwich enzyme immunoassay. The microtiter plate provided in this kit has been pre-coated with an antibody specific to Human FOXP3. Standards or samples are added to the appropriate microtiter plate wells then with a biotin-conjugated antibody specific to Human FOXP3. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After TMB substrate solution is added, only those wells that contain Human FOXP3, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450nm ± 10nm. The concentration of Human FOXP3 in the samples is then determined by comparing the OD of the samples to the standard curve.

For use with: tissue homogenates, cell lysates, cell culture supernates, and other biological fluids.

For Research Use Only. Not for use in diagnostic procedures.

Target Information

Transcriptional regulator which is crucial for the development and inhibitory function of regulatory T-cells (Treg) (PubMed:17377532, PubMed:21458306, PubMed:30513302, PubMed:23947341, PubMed:24354325, PubMed:24722479, PubMed:24835996). Plays an essential role in maintaining homeostasis of the immune system by allowing the acquisition of full suppressive function and stability of the Treg lineage, and by directly modulating the expansion and function of conventional T-cells (PubMed:23169781). Can act either as a transcriptional repressor or a transcriptional activator depending on its interactions with other transcription factors, histone acetylases and deacetylases (PubMed:17377532, PubMed:21458306, PubMed:23947341, PubMed:24354325, PubMed:24722479). The suppressive activity of Treg involves the coordinate activation of many genes, including CTLA4 and TNFRSF18 by FOXP3 along with repression of genes encoding cytokines such as interleukin-2 (IL2) and interferon-gamma (IFNG) (PubMed:17377532, PubMed:21458306, PubMed:23947341, PubMed:24354325, PubMed:24722479). Inhibits cytokine production and T-cell effector function by repressing the activity of two key transcription factors, RELA and NFATC2 (PubMed:15790681). Mediates transcriptional repression of IL2 via its association with histone acetylase KAT5 and histone deacetylase HDAC7 (PubMed:17360565). Can activate the expression of TNFRSF18, IL2RA and CTLA4 and repress the expression of IL2 and IFNG via its association with transcription factor RUNX1 (PubMed:17377532). Inhibits the differentiation of IL17 producing helper T-cells (Th17) by antagonizing RORC function, leading to down-regulation of IL17 expression, favoring Treg development (PubMed:18368049). Inhibits the transcriptional activator activity of RORA (PubMed:18354202). Can repress the expression of IL2 and IFNG via its association with transcription factor IKZF4 (By similarity).

GENE ID	50943
SWISS PROT	Q9BZS1
SYNONYMS	FOX-P3; AIID; DIETER; IPEX; JM2; PIDX; XPID; SCURFIN; Immune Dysregulation,Polyendocrinopathy,Enteropathy,X-Linked

Materials Supplied

Kit Components	96 Wells Quantity/Size
Pre-Coated Microplate	48T: 6 strips x 8 wells; 96T: 12 strips x 8 wells
Standard (Lyophilized)	48T: 1 vial; 96T: 2 vials
Biotinylated Antibody (100×)	48T: 60 μL; 96T: 120 μL
Streptavidin-HRP (100×)	48T: 60 μL; 96T: 120 μL
Standard/Sample Diluent Buffer	48T: 10 mL; 96T: 20 mL
Biotinylated Antibody Diluent	48T: 6 mL; 96T: 12 mL
HRP Diluent	48T: 6 mL; 96T: 12 mL
Wash Buffer (25×)	48T: 10 mL; 96T: 20 mL
TMB Substrate Solution	48T: 6 mL; 96T: 10 mL
Stop Reagent	48T: 3 mL; 96T: 6 mL
Plate Covers	48T: 1 piece; 96T: 2 pieces

Storage

Storage

*If the kit is opened, Store the whole kit at 4°C. If the kit is not used up in 1 week. Store the Pre-Coated Microplate, Standard ,Biotinylated Antibody and Streptavidin-HRP at -20°C, the rest reagents at 4°C, please used up within 6 months. *If the kit is not opened, store the whole kit: 4°C(short time storage, valid for 6 months); -20°C (long-term storage, valid for 1 year). Avoid repeated freeze-thaw cycles.

Performance Characteristics

REPEATABILITY	Intra-assay Precision (Precision within an assay)：CV% < 8% Three samples of known concentration were tested twenty times on 1 plate to assess intra-assay precision. Inter-assay Precision (precision between assays)：CV% < 10% Three samples of known concentration were tested in forty separate assays to assess inter-assay precision.
SENSITIVITY	The minimum detectable dose was 0.112ng/mL.
ASSAY RANGE	0.32–20ng/mL
SPECIFICITY	This assay has high sensitivity and excellent specificity for detection of Human FOXP3. No significant cross-reactivity or interference between Human FOXP3 and analogues was observed.