Human Cystatin 4 (CST4) ELISA Kit | CST4 elisa kit

Human Cystatin 4 (CST4) ELISA Kit

Cat. Num. AAA451186

• Reactivity: Human
• Synonyms: Cystatin 4 (CST4); Human Cystatin 4 (CST4) ELISA Kit; Cystatin S; Salivary acidic protein 1; Cystatin-SA-III; CST4 elisa kit

• Reactivity: Human
• Specificity: This assay has high sensitivity and excellent specificity for detection of CST4. No significant cross-reactivity or interference between CST4 and analogues was observed.
• Sequence Length: 141

• Samples: Serum, plasma, tissue homogenates, cell lysates, cell culture supernates and other biological fluids.
• Assay Type: Sandwich
• Detection Range: 0.156-10ng/mL
• Sensitivity: 0.053ng/mL
• Intra-assay Precision: Intra-assay Precision (Precision within an assay): 3 samples with low, middle and high level CST4 were tested 20 times on one plate, respectively. Intra-Assay: CV<10%
• Inter-assay Precision: Inter-assay Precision (Precision between assays): 3 samples with low, middle and high level CST4 were tested on 3 different plates, 8 replicates in each plate. CV(%) = SD/meanX100. Inter-Assay: CV<12%
• Preparation and Storage: For unopened kit, all reagents should be kept according to the labels on vials. The TMB Substrate, Wash Buffer, Stop Solution should be stored at 4 degree C. All others should be stored at -20 degree C.

Typical Testing Data/Standard Curve (for reference only)

Related Product Information for CST4 elisa kit

Intended Uses: The kit is a sandwich enzyme immunoassay for in vitro quantitative measurement of CST4 in human serum, plasma, tissue homogenates, cell lysates, cell culture supernates and other biological fluids.

Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to CST4. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific to CST4. 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 CST4, 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 CST4 in the samples is then determined by comparing the O.D. of the samples to the standard curve.

NCBI and Uniprot Product Information

• NCBI GI #: 4503109
• NCBI GeneID: 1472
• NCBI Accession #: NP_001890.1
• NCBI GenBank Nucleotide #: NM_001899.2
• UniProt Accession #: P01036; Q9UBI5; Q9UCS9
• Molecular Weight: 16,214 Da
• NCBI Official Full Name: cystatin-S
• NCBI Official Synonym Full Names: cystatin S
• NCBI Official Symbol: CST4
• NCBI Protein Information: cystatin-S
• UniProt Protein Name: Cystatin-S
• Protein Family: Cystatin
• UniProt Gene Name: CST4

NCBI Description

The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions. The cystatin locus on chromosome 20 contains the majority of the type 2 cystatin genes and pseudogenes. This gene is located in the cystatin locus and encodes a type 2 salivary cysteine peptidase inhibitor. The protein is an S-type cystatin, based on its high level of expression in saliva, tears and seminal plasma. The specific role in these fluids is unclear but antibacterial and antiviral activity is present, consistent with a protective function. [provided by RefSeq, Jul 2008]

Uniprot Description

This protein strongly inhibits papain and ficin, partially inhibits stem bromelain and bovine cathepsin C, but does not inhibit porcine cathepsin B or clostripain. Papain is inhibited non-competitively.