Overview

Introduction
Cathepsin B is an enzymatic protein belonging to the peptidase (or protease) families. In humans, it is coded by the CTSB gene. This protein is a lysosomal cysteine protease composed of a dimer of disulfide-linked heavy and light chains, both produced from a single protein precursor. It can degrade β-amyloid precursor protein into harmless fragments. Thus, it is conceivable cathepsin B may play a pivotal role in the natural defense against Alzheimer's disease. Overexpression of cathepsin B has been associated with esophageal adenocarcinoma and other tumors.

Principle of the Assay  
This kit was based on sandwich enzyme-linked immune-sorbent assay technology. Anti- Cathepsin B polyclonal antibody was pre-coated onto 96-well plates. And the biotin conjugated anti- Cathepsin B polyclonal antibody was used as detection antibodies. The standards, test samples and biotin conjugated detection antibody were added to the wells subsequently, and wash with wash buffer. Avidin-Biotin-Peroxidase Complex was added and unbound conjugates were washed away with wash buffer. TMB substrates were used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the Cathepsin B amount of sample captured in plate. Read the O.D. absorbance at 450nm in a microplate reader, and then the concentration of Cathepsin B can be calculated.

Range: 156 pg/ml-10,000 pg/ml

Sensitivity < 5 pg/ml

Storage and Expiration: Store at 2-8℃ for 4 months, or at -20℃ for 8 months.

Application: For quantitative detection of Cathepsin B in human serum, plasma, body fluids, tissue lysates or cell culture supernates

Kit components
1.     One 96-well plate pre-coated with anti-Human Cathepsin B antibody
2.     Lyophilized Human Cathepsin B standards: 2 tubes (10ng / tube)                    
3.     Sample / Standard diluent buffer: 30 ml
4.     Biotin conjugated anti-Human Cathepsin B antibody (Concentrated): 130 μl. Dilution: 1:100
5.     Antibody diluent buffer: 12 ml
6.     Avidin-Biotin-Peroxidase Complex (ABC) (Concentrated): 130 μl. Dilution: 1:100
7.     ABC diluent buffer: 12 ml
8.     TMB substrate: 10 ml
9.     Stop solution: 10 ml
10.   Wash buffer (25X): 30 ml

Note: Reconstitute standards and test samples with Kit Component 3.

Gene Information

OMIM: 116810
Swiss Port: P07858
Gene ID: 1508

Other Information

Please check datasheet for protocol.