Stefin B Colorimetric Cell-Based ELISA Kit (CBCAB00873)

Product Name:	Stefin B Colorimetric Cell-Based ELISA Kit
Product Code:	CBCAB00873
ELISA Type:	Cell-Based
Target:	Stefin B
Reactivity:	Human, Rat
Dynamic Range:	> 5000 Cells
Detection Method:	Colorimetric 450 nmStorage/Stability:4°C/6 Months
Format:	96-Well Microplate

The Stefin B Colorimetric Cell-Based ELISA Kit is a convenient, lysate-free, high throughput and sensitive assay kit that can detect Stefin B protein expression profile in cells. The kit can be used for measuring the relative amounts of Stefin B in cultured cells as well as screening for the effects that various treatments, inhibitors (ie siRNA or chemicals), or activators have on Stefin B.

Qualitative determination of Stefin B concentration is achieved by an indirect ELISA format. In essence, Stefin B is captured by Stefin B-specific primary antibodies while the HRP-conjugated secondary antibodies bind the Fc region of the primary antibody. Through this binding, the HRP enzyme conjugated to the secondary antibody can catalyze a colorimetric reaction upon substrate addition. Due to the qualitative nature of the Cell-Based ELISA, multiple normalization methods are needed:

1.	A monoclonal antibody specific for human GAPDH is included to serve as an internal positive control in normalizing the target absorbance values.
2.	Following the colorimetric measurement of HRP activity via substrate addition, the Crystal Violet whole-cell staining method may be used to determine cell density. After staining, the results can be analysed by normalizing the absorbance values to cell amounts, by which the plating difference can be adjusted.

Database Information:	Gene ID: 1476, UniProt ID: P04080, OMIM: 601145, Unigene: Hs.695
Gene Symbol:	CSTB
Sub Type:	None

UniProt Protein Function:	CSTB: This is an intracellular thiol proteinase inhibitor. Tightly binding reversible inhibitor of cathepsins L, H and B. Defects in CSTB are the cause of progressive myoclonic epilepsy type 1 (EPM1). EPM1 is an autosomal recessive disorder characterized by severe, stimulus-sensitive myoclonus and tonic-clonic seizures. The onset, occurring between 6 and 13 years of age, is characterized by convulsions. Myoclonus begins 1 to 5 years later. The twitchings occur predominantly in the proximal muscles of the extremities and are bilaterally symmetrical, although asynchronous. At first small, they become late in the clinical course so violent that the victim is thrown to the floor. Mental deterioration and eventually dementia develop. Belongs to the cystatin family.
UniProt Protein Details:	Protein type:Inhibitor Chromosomal Location of Human Ortholog: 21q22.3 Cellular Component: extracellular space; cytoplasm; nucleolus Molecular Function:protease binding; endopeptidase inhibitor activity; cysteine protease inhibitor activity Biological Process: negative regulation of proteolysis; regulation of apoptosis; adult locomotory behavior; negative regulation of peptidase activity Disease: Myoclonic Epilepsy Of Unverricht And Lundborg
NCBI Summary:	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 kininogens. This gene encodes a stefin that functions as an intracellular thiol protease inhibitor. The protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. The protein is thought to play a role in protecting against the proteases leaking from lysosomes. Evidence indicates that mutations in this gene are responsible for the primary defects in patients with progressive myoclonic epilepsy (EPM1). [provided by RefSeq, Jul 2008]
UniProt Code:	P04080
NCBI GenInfo Identifier:	1706278
NCBI Gene ID:	1476
NCBI Accession:	P04080.2
UniProt Related Accession:	P04080
Molecular Weight:	11,140 Da
NCBI Full Name:	Cystatin-B
NCBI Synonym Full Names:	cystatin B (stefin B)
NCBI Official Symbol:	CSTB
NCBI Official Synonym Symbols:	PME; ULD; CST6; EPM1; STFB; EPM1A
NCBI Protein Information:	cystatin-B; CPI-B; liver thiol proteinase inhibitor
UniProt Protein Name:	Cystatin-B
UniProt Synonym Protein Names:	CPI-B; Liver thiol proteinase inhibitor; Stefin-B
Protein Family:	Cystatin
UniProt Gene Name:	CSTB
UniProt Entry Name:	CYTB_HUMAN

Component	Quantity
96-Well Cell Culture Clear-Bottom Microplate	2 plates
10X TBS	24 mL
Quenching Buffer	24 mL
Blocking Buffer	50 mL
15X Wash Buffer	50 mL
Primary Antibody Diluent	12 mL
100x Anti-Phospho Target Antibody	60 µL
100x Anti-Target Antibody	60 µL
Anti-GAPDH Antibody	60 µL
HRP-Conjugated Anti-Rabbit IgG Antibody	12 mL
HRP-Conjugated Anti-Mouse IgG Antibody	12 mL
SDS Solution	12 mL
Stop Solution	24 mL
Ready-to-Use Substrate	12 mL
Crystal Violet Solution	12 mL
Adhesive Plate Seals	2 seals

The following materials and/or equipment are NOT provided in this kit but are necessary to successfully conduct the experiment:

Microplate reader able to measure absorbance at 450 nm and/or 595 nm for Crystal Violet Cell Staining (Optional)
Micropipettes with capability of measuring volumes ranging from 1 µL to 1 ml
37% formaldehyde (Sigma Cat# F-8775) or formaldehyde from other sources
Squirt bottle, manifold dispenser, multichannel pipette reservoir or automated microplate washer
Graph paper or computer software capable of generating or displaying logarithmic functions
Absorbent papers or vacuum aspirator
Test tubes or microfuge tubes capable of storing ≥1 ml
Poly-L-Lysine (Sigma Cat# P4832 for suspension cells)
Orbital shaker (optional)
Deionized or sterile water

*Note: Protocols are specific to each batch/lot. For the correct instructions please follow the protocol included in your kit.

Step	Procedure
1.	Seed 200 µL of 20,000 adherent cells in culture medium in each well of a 96-well plate. The plates included in the kit are sterile and treated for cell culture. For suspension cells and loosely attached cells, coat the plates with 100 µL of 10 µg/ml Poly-L-Lysine (not included) to each well of a 96-well plate for 30 minutes at 37°C prior to adding cells.
2.	Incubate the cells for overnight at 37°C, 5% CO2.
3.	Treat the cells as desired.
4.	Remove the cell culture medium and rinse with 200 µL of 1x TBS, twice.
5.	Fix the cells by incubating with 100 µL of Fixing Solution for 20 minutes at room temperature. The 4% formaldehyde is used for adherent cells and 8% formaldehyde is used for suspension cells and loosely attached cells.
6.	Remove the Fixing Solution and wash the plate 3 times with 200 µL 1x Wash Buffer for five minutes each time with gentle shaking on the orbital shaker. The plate can be stored at 4°C for a week.
7.	Add 100 µL of Quenching Buffer and incubate for 20 minutes at room temperature.
8.	Wash the plate 3 times with 1x Wash Buffer for 5 minutes each time.
9.	Add 200 µL of Blocking Buffer and incubate for 1 hour at room temperature.
10.	Wash 3 times with 200 µL of 1x Wash Buffer for 5 minutes each time.
11.	Add 50 µL of 1x primary antibodies (Anti-Stefin B Antibody and/or Anti-GAPDH Antibody) to the corresponding wells, cover with Parafilm and incubate for 16 hours (overnight) at 4°C. If the target expression is known to be high, incubate for 2 hours at room temperature.
12.	Wash 3 times with 200 µL of 1x Wash Buffer for 5 minutes each time.
13.	Add 50 µL of 1x secondary antibodies (HRP-Conjugated AntiRabbit IgG Antibody or HRP-Conjugated Anti-Mouse IgG Antibody) to corresponding wells and incubate for 1.5 hours at room temperature.
14.	Wash 3 times with 200 µL of 1x Wash Buffer for 5 minutes each time.
15.	Add 50 µL of Ready-to-Use Substrate to each well and incubate for 30 minutes at room temperature in the dark.
16.	Add 50 µL of Stop Solution to each well and read OD at 450 nm immediately using the microplate reader.

(Additional Crystal Violet staining may be performed if desired – details of this may be found in the kit technical manual.)