Human Cathepsin B PicoKine® Quick ELISA Kit

Cathepsin B is an enzymatic protein belonging to the peptidase or protease families. In humans, it is coded by the CTSB gene.1, 2 And this gene is mapped to chromosome 8p22.3 The protein encoded by this gene is a lysosomal cysteine proteinase composed of a dimer of disulfide-linked heavy and light chains, both produced from a single protein precursor. It is a member of the peptidase C1 family. Cathepsin B was once suspected as a candidate protease participating in the conversion of beta-amyloid precursor protein into the amyloid plaques found in Alzheimer's disease patients. However, this function is now known to be mediated by BACE1 protease. It is now thought that cathepsin B can degrade beta-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.4 Overexpression of cathepsin B has been associated with esophageal adenocarcinoma and other tumors. At least five transcript variants encoding the same protein have been found for this gene. The standard product used in this kit is recombinant human Cathepsin B with the molecular mass of 37KDa.

Lots Lot 1 (pg/ml) Lot 2 (pg/ml) Lot 3 (pg/ml) Lot 4 (pg/ml) Mean (pg/ml) Standard Deviation CV (%) Sample 1 242 251 245 277 254 15.99 6.3% Sample 2 1834 1763 1647 1547 1698 56.03 3.3% Sample 3 4362 4260 3862 4631 4279 282.4 6.6% Lots Lot 1 (pg/ml) Lot 2 (pg/ml) Lot 3 (pg/ml) Lot 4 (pg/ml) Mean (pg/ml) Standard Deviation CV (%) Lots Lot 1 (pg/ml) Lot 2 (pg/ml) Lot 3 (pg/ml) Lot 4 (pg/ml) Mean (pg/ml) Standard Deviation CV (%) Sample 1 242 251 245 277 254 15.99 6.3% Sample 1 242 251 245 277 254 15.99 6.3% Sample 2 1834 1763 1647 1547 1698 56.03 3.3% Sample 2 1834 1763 1647 1547 1698 56.03 3.3% Sample 3 4362 4260 3862 4631 4279 282.4 6.6% Sample 3 4362 4260 3862 4631 4279 282.4 6.6%

Intra-Assay Precision Inter-Assay Precision Sample 1 2 3 1 2 3 n 16 16 16 24 24 24 Mean (pg/ml) 242 1834 4362 264 1932 4096 Standard deviation 16.7 126.55 322.79 20.86 142.97 372.74 CV (%) 6.9% 6.9% 7.4% 7.9% 7.4% 9.1% Intra-Assay Precision Inter-Assay Precision Sample 1 2 3 1 2 3 n 16 16 16 24 24 24 Mean (pg/ml) 242 1834 4362 264 1932 4096 Standard deviation 16.7 126.55 322.79 20.86 142.97 372.74 CV (%) 6.9% 6.9% 7.4% 7.9% 7.4% 9.1% Intra-Assay Precision Inter-Assay Precision Intra-Assay Precision Inter-Assay Precision Sample 1 2 3 1 2 3 Sample 1 2 3 1 2 3 n 16 16 16 24 24 24 n 16 16 16 24 24 24 Mean (pg/ml) 242 1834 4362 264 1932 4096 Mean (pg/ml) 242 1834 4362 264 1932 4096 Standard deviation 16.7 126.55 322.79 20.86 142.97 372.74 Standard deviation 16.7 126.55 322.79 20.86 142.97 372.74 CV (%) 6.9% 6.9% 7.4% 7.9% 7.4% 9.1% CV (%) 6.9% 6.9% 7.4% 7.9% 7.4% 9.1%

Description|Quantity|Volume Anti-tag Pre-coated 96-well Strip Microplate|1|12 strips of 8 wells Standard||2 Antibody A|1|3ml Antibody B|1|3ml Sample Diluent|1|15ml TBS-T Wash Buffer (25x) |1|12ml Color Developing Reagent (TMB) |1|10ml Stop Solution|1|10ml Adhesive Plate Sealers|2|Piece

Concentration (pg/ml) 0 156 312 625 1250 2500 5000 10000 O.D. 0.107 0.243 0.348 0.539 0.894 1.445 2.041 2.443 Concentration (pg/ml) 0 156 312 625 1250 2500 5000 10000 O.D. 0.107 0.243 0.348 0.539 0.894 1.445 2.041 2.443 Concentration (pg/ml) 0 156 312 625 1250 2500 5000 10000 Concentration (pg/ml) 0 156 312 625 1250 2500 5000 10000 O.D. 0.107 0.243 0.348 0.539 0.894 1.445 2.041 2.443 O.D. 0.107 0.243 0.348 0.539 0.894 1.445 2.041 2.443

Microplate Reader capable of reading absorbance at 450nm. Automated plate washer (optional) Pipettes and pipette tips capable of precisely dispensing 0.5 μl through 1 ml volumes of aqueous solutions. Multichannel pipettes are recommended for large amount of samples. Deionized or distilled water. 500ml graduated cylinders. Test tubes for dilution. Horizontal orbital microplate shaker capable of maintaining a speed of 500 rpm, amplitude 3mm.