Human IGFBP-6 (insulin-like growth factor binding protein 6) ELISA Kit

Sample

Serum, plasma or other body fluids

Species Reactivity

Human

Detection Method

sELISA

Intended Use

This enzyme immunoassay kit is suited for measuring IGFBP-6 in human serum / plasma and other body fluids. For research use only. Not for diagnostic procedures.

Contents of Kit

1. Microtiter plate: ready for use, coated with rabbit-anti-hIGFBP-6-antibody. Wells are separately breakable. (8x12) wells
2. Standards (A-E): lyophilized, (recombinant mouse IGFBP-6), concentrations are given on vial labels and on quality certificate. 5 x 750 μL
3. Control Serum 1 (KS1): lyophilized, (human serum), concentration is given on quality certificate. 1 x 250 μL
4. Control Serum 2 (KS2): lyophilized, (human serum), concentration is given on quality certificate. 1 x 250 μL
5. Antibody Conjugate (AK): ready for use, contains rabbit biotinylated anti-hIGFBP-6 antibody. 1 x 12 mL
6. Enzyme Conjugate (EK): contains HRP (Horseradish-Peroxidase)-labeled Streptavidin. 1 x 12 mL
7. Dilution Buffer (VP): ready for use. Please shake before use! 1 x 120 mL
8. Washing Buffer (WP): 20-fold concentrated solution. 1 x 50 mL
9. Substrate (S): ready for use, horseradish-peroxidase-(HRP) substrate, stabilised Tetramethylbencidine. 1 x 12 mL
10. Stopping Solution (SL): ready for use, 0.2 M sulfuric acid. 1 x 12 mL
11. Sealing Tape: for covering the microtiter plate. 2

Storage

Store the kit at 2-8°C after receipt until its expiry date. The lyophilized reagents should be stored at –20 °C after reconstitution. Avoid repeated thawing and freezing.
The shelf life of the components after initial opening is warranted for 4 weeks, store the unused strips and microtiter wells airtight together with the desiccant at 2-8°C in the clip-lock bag, use in the frame provided. The reconstituted components standards A-E and Control Sera KS1 and KS2 must be stored at –20°C (max. 4 weeks). For further use, thaw quickly but gently (avoid temperature increase above room temperature and avoid excessive vortexing). Up to 3 of the freeze-thaw cycles did not influence the assay. The 1:20 diluted Washing Buffer WP is 4 weeks stable at 2-8°C

Precision

Intra-Assay Variance
IGFBP-6 content of four samples was measured at least 12 times in the same assay. The measured coefficient of variation (CV) is 1.1% on average.
Inter-Assay Variance
IGFBP-6 content of 12 serum samples was measured in 11 or more independent assays. The measured coefficient of variation (CV) is 6.67% on average.

Sensitivity

Sensitivity was assessed by measuring the signal of the blank at least 8 times within one test and calculating the theoretical concentration of 2SD of the mean signal measured. The analytical sensitivity of the Human IGFBP-6 ELISA Kit is on average 0.026 ng/mL, measured in 4 independent tests (Range 0.004 to 0.029 ng/mL).
Based on the minimal required dilution (1:20) and lowest calibration standard (0.1 ng/mL) the lower limit of quantification is 2 ng/mL in the undiluted sample.

General Description

The Insulin-like Growth Factor 6 (IGFBP-6) is part of the IGF-System which consists of several binding proteins (1-6) and IGF-I and –II. The Insulin-like Growth Factors are involved in the control of human growth and regulated themselves by their binding proteins. The IGFBPs show high amino acid sequence homology, they have conserved N- and C-terminal domains which are involved in IGF-binding. In contrast the central linker region is highly variable. This region is not directly involved in IGF-binding but influences stability and localisation of the IGFBP / IGF complex and can be modified by glycosylation and phosphorylation.
IGFBP-6 a protein of 213 amino acids and about 34 kDa is somewhat special because of only three disulphide bridges in the C-terminal domain, resulting in a significantly higher affinity (50fold) for IGF-II than IGF-I. Further IGFBP-6 can be O-glycosylated and is cleaved by cathepsin-D-like acid protease, neutral serine protease as well as MMP-2/-7/-9/-12.
Main proposed function of IGFBP-6 is the regulation of the biological availability of IGF-II and thereby it influences cell proliferation, differentiation, migration and survival. Further IGFindependent as well as intra- and nuclear actions of IGFBP-6 are discussed. IGFindependent actions might be transmitted by prohibitin-2 as a potential cell surface receptor. Physiologically IGFBP-6 might be involved in senescence, angiogenesis and cancer. But a clear clinical indication for measurement of plasma IGFBP-6 needs to be determined.

Standard Curve

The following data is for demonstration only and cannot be used in place of data generation at the time of assay.

The exemplary shown calibration curve in Figure below cannot be used for calculation of your test results. You have to establish a calibration curve for each test you conduct!