Human Virus Induced Signaling Adapter (VISA) ELISA Kit

Principle of the Assay

The microtiter plate provided in this kit has been pre-coated with an antibody specific to VISA. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific to VISA. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. After the TMB substrate solution is added, only those wells that contain VISA, 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 VISA in the samples is then determined by comparing the O.D. of the samples to the standard curve.

For Use with serum, plasma, and cell culture supernatants. For Research Use Only. Not for use in diagnostic procedures.

Target Information

Required for innate immune defense against viruses (PubMed:16125763, PubMed:16127453, PubMed:16153868, PubMed:16177806, PubMed:19631370, PubMed:20451243, PubMed:23087404, PubMed:20127681, PubMed:21170385). Acts downstream of DHX33, DDX58/RIG-I and IFIH1/MDA5, which detect intracellular dsRNA produced during viral replication, to coordinate pathways leading to the activation of NF-kappa-B, IRF3 and IRF7, and to the subsequent induction of antiviral cytokines such as IFNB and RANTES (CCL5) (PubMed:16125763, PubMed:16127453, PubMed:16153868, PubMed:16177806, PubMed:19631370, PubMed:20451243, PubMed:23087404, PubMed:25636800, PubMed:20127681, PubMed:21170385, PubMed:20628368, PubMed:33110251). Peroxisomal and mitochondrial MAVS act sequentially to create an antiviral cellular state (PubMed:20451243). Upon viral infection, peroxisomal MAVS induces the rapid interferon-independent expression of defense factors that provide short-term protection, whereas mitochondrial MAVS activates an interferon-dependent signaling pathway with delayed kinetics, which amplifies and stabilizes the antiviral response (PubMed:20451243). May activate the same pathways following detection of extracellular dsRNA by TLR3 (PubMed:16153868). May protect cells from apoptosis (PubMed:16125763).

GENE ID	57506
SWISS PROT	Q7Z434
SYNONYMS	CARDIF; IPS1; MAVS; Mitochondrial Antiviral-Signaling Protein; Interferon beta promoter stimulator protein 1; CARD Adaptor Inducing IFN-beta; NF-kappa-B-activating protein 031N

Materials Supplied

Kit Components	96 Wells Quantity/Size
Pre-coated, ready-to-use 96-well strip plate	1 plate
Plate sealer for 96 wells	2
Standard	2 tubes
Diluent buffer	1 bottle
Detection Reagent A	1 bottle
Detection Reagent B	1 bottle
TMB Substrate	1 tube
Stop Solution	1 tube
Wash Buffer (30 ℅ concentrate)	1 tube
Product data sheet	1 copy

Storage

The TMB Substrate, Wash Buffer (30X concentrate), and the Stop Solution should be stored at 4°C upon receipt, while the other items should be stored at -20°C.

Performance Characteristics

REPEATABILITY	Intra-assay Precision (Precision within an assay): 3 samples with low, middle, and high-level VISA were tested 20 times on one plate, respectively. Inter-assay Precision (Precision between assays): 3 samples with low, middle, and high-level VISA were tested on 3 different plates, with 8 replicates in each plate. CV(%) = SD/meanX100 Intra-Assay: CV<10% Inter-Assay: CV<12%
SENSITIVITY	The minimum detectable dose was 0.068ng/mL.
ASSAY RANGE	0.156-10ng/mL
SPECIFICITY	This assay has high sensitivity and excellent specificity for the detection of VISA. No significant cross-reactivity or interference between VISA and analogs was observed. Note: Limited by current skills and knowledge, it is impossible to perform all possible cross-reactivity detection tests between VISA and all analogs, therefore, cross reactivity may still exist.