IGFBP-3 Colorimetric Cell-Based ELISA Kit (CBCAB00705)

Product Name:	IGFBP-3 Colorimetric Cell-Based ELISA Kit
Product Code:	CBCAB00705
ELISA Type:	Cell-Based
Target:	IGFBP-3
Reactivity:	Human, Mouse
Dynamic Range:	> 5000 Cells
Detection Method:	Colorimetric 450 nmStorage/Stability:4°C/6 Months
Format:	96-Well Microplate

The IGFBP-3 Colorimetric Cell-Based ELISA Kit is a convenient, lysate-free, high throughput and sensitive assay kit that can detect IGFBP-3 protein expression profile in cells. The kit can be used for measuring the relative amounts of IGFBP-3 in cultured cells as well as screening for the effects that various treatments, inhibitors (ie siRNA or chemicals), or activators have on IGFBP-3.

Qualitative determination of IGFBP-3 concentration is achieved by an indirect ELISA format. In essence, IGFBP-3 is captured by IGFBP-3-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: 3486, UniProt ID: P17936, OMIM: 146732, Unigene: Hs.450230/Hs.697535
Gene Symbol:	IGFBP3
Sub Type:	None

UniProt Protein Function:	IGFBP3: IGF-binding proteins prolong the half-life of the IGFs and have been shown to either inhibit or stimulate the growth promoting effects of the IGFs on cell culture. They alter the interaction of IGFs with their cell surface receptors. Also exhibits IGF-independent antiproliferative and apoptotic effects mediated by its receptor TMEM219/IGFBP-3R.
UniProt Protein Details:	Protein type:Secreted; Cell development/differentiation; Secreted, signal peptide Chromosomal Location of Human Ortholog: 7p12.3 Cellular Component: extracellular region; extracellular space; insulin-like growth factor binding protein complex; nucleus Molecular Function:fibronectin binding; insulin-like growth factor binding; insulin-like growth factor I binding; insulin-like growth factor II binding; metal ion binding; protein binding; protein tyrosine phosphatase activator activity Biological Process: apoptosis; cellular protein metabolic process; negative regulation of cell proliferation; negative regulation of protein amino acid phosphorylation; negative regulation of signal transduction; negative regulation of smooth muscle cell migration; negative regulation of smooth muscle cell proliferation; osteoblast differentiation; positive regulation of apoptosis; positive regulation of catalytic activity; positive regulation of insulin-like growth factor receptor signaling pathway; positive regulation of MAPKKK cascade; positive regulation of myoblast differentiation; protein amino acid phosphorylation; regulation of cell growth; regulation of insulin-like growth factor receptor signaling pathway
NCBI Summary:	This gene is a member of the insulin-like growth factor binding protein (IGFBP) family and encodes a protein with an IGFBP domain and a thyroglobulin type-I domain. The protein forms a ternary complex with insulin-like growth factor acid-labile subunit (IGFALS) and either insulin-like growth factor (IGF) I or II. In this form, it circulates in the plasma, prolonging the half-life of IGFs and altering their interaction with cell surface receptors. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008]
UniProt Code:	P17936
NCBI GenInfo Identifier:	146327827
NCBI Gene ID:	3486
NCBI Accession:	P17936.2
UniProt Secondary Accession:	P17936,Q2V509, Q6P1M6, Q9UCL4, A4D2F5, D3DVM0,
UniProt Related Accession:	P17936
Molecular Weight:	32,223 Da
NCBI Full Name:	Insulin-like growth factor-binding protein 3
NCBI Synonym Full Names:	insulin like growth factor binding protein 3
NCBI Official Symbol:	IGFBP3
NCBI Official Synonym Symbols:	IBP3; BP-53
NCBI Protein Information:	insulin-like growth factor-binding protein 3
UniProt Protein Name:	Insulin-like growth factor-binding protein 3
Protein Family:	Insulin-like growth factor-binding protein
UniProt Gene Name:	IGFBP3
UniProt Entry Name:	IBP3_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-IGFBP-3 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.)