| 产品详情 |
| Edit |   |
|---|
| Product Name | Functional IGFBP-3 ALICIA |
|---|
| Description | The new principle in functional IGFBP-3 testing: IGFBP-3 ALICIA - A Ligand Capture Immuno Assay! Do you know, if your IGFBP-3 assay measures IGFBP-3 fragments? None, all, some...? Are the results of your assay affected by fragments? The problem: In serum and other body fluids IGFBP-3 is cleaved by proteases, that generate fragments with reduced or no affinity to IGF?s. Increased proteolytical activities have been observed in various clinical and physiological conditions, as pregnancy, cancer. In samples with high protease activities, the results obtained by conventional immunoassays may be affected by fragments. Discrepancies between the results obtained by western-ligand blotting or a recently described ligand immunofunctional assay (methods that measure \functional IGFBP-3\), and \immunoreactive IGFBP-3\ (measured by conventional immunoassays) have been observed (1-9). The solution: ibt IGFBP-3 ALICIA The ibt Functional IGFBP-3 Ligand Capture Immunoassay is designed to measure only functional IGFBP-3 and functional fragments, i. e. IGFBP-3 and fragments that are able to bind IGF?s. Fragments, that have lost their affinity are not bound to the plate and washed away! Features of the ibt IGFBP-3 ALICIA The assay uses a biotinylated ligand, that is also used in the ibt western-ligand blotting kits. The problems associated with radioactive ligands are therefore avoided. The new test principle combines the advantages of western-ligand blotting and ELISA, as shown in the reaction schedule. The capturing procedure is integrated in a standard ELISA procedure. No filtration steps are required. The total incubation time is only 3.5 hours. All incubation steps are performed at room temperature without shaking. Assay sensitivity is adjusted to physiological values, standard range 1 600-100 ng/ml (1.6-0.1 mg/l). The new test principle: During sample preparation natural IGF?s are released from their IGFBP?s. Functional IGFBP?s are labelled with an excess of biotinylated IGF-II and are bound to a microtiterplate coated with Streptavidin. In the same step, the specific primary antibody binds to IGFBP-3. IGFBP fragments, that have lost their affinities are not bound and are washed away in the subsequent washing step.The primary antibody, which is bound to functional IGFBP-3 is then detected by a secondary peroxidase-conjugate antibody. The reaction is stopped by addition of acid and the blue colour turns to yellow. The measured absorbance is directly proportional to the quantity of functional IGFBP-3. Background Insulin-like growth factors (IGF) I and II are peptides that are growth factors for a broad range of cell types. In serum and other body fluids more than 99 % of the IGF?s are bound to insulin-like growth factor binding proteins (IGFBP?s). Six high affinity binding proteins have been characterised until today.In human serum IGFBP-3 has the highest concentration and more than 95 % of the IGF?s are bound to the single binding site of IGFBP-3. It prolongs the shelf life of IGF?s and is the main circulating reservoir for IGF-I and -II.The bioavailability of IGF-I and -II is regulated by a complex system. One of the mechanisms is the release of bound IGF?s from IGFBP?s by proteases, generating fragments with reduced or no affinity for the IGF?s. For IGFBP-3, there are reports on a number of proteolytical fragments of 30 kDa, 22 - 25 kDa and 16 kDa. Conventional Applications: The ibt Functional IGFBP-3 ALICIA has been calibrated using a non-proteolysed standard. The results in sera without IGFBP-3 proteolysis can be correlated with the results of conventional assays. The applications of IGFBP-3 measurement include:Assessment of short stature in children: GH levels fluctuates throughout the day and the half life is only 15-20 minutes. In contrast IGFBP-3 exhibits much less diurnal variation and therefore a single measurement reflects the integrated GH level.IGFBP-3 measurements are useful for monitoring the efficacy of treatment for GH deficiency. In acromegaly, serum IGFBP-3 levels are useful as a marker of GH excess. In addition, IGFBP-3 measurement may be useful in assessing efficiency of surgical cure of somatotroph tumors.IGFBP-3 measurements may also be helfpful in the evaluation of nutritional status. New applications: In addition to conventional applications the ibt IGFBP-3 ALICIA may be a helpful tool for IGFBP-3 measurement in all physiological conditions and diseases with elevated IGFBP-3 protease activities, where conventional immunoassays may give wrong results. Proteases have been observed in serum and other body fluids as peritoneal fluid, lymph, synovial fluid, ovarian follicular fluid, seminal plasma and amniotic fluid. Characterized proteases, that cleave IGFBP-3 are e.g. Prostate Specific Antigen (PSA), Plasmin, Thrombin, Cathepsin D, MMP-1, -2, - 9 and gamma NGF. Elevated protease activities have been observed in a number of physiological conditions and diseases, as e.g. pregnancy, patients with growth hormone receptor insensitivity, Turner syndrome (7), catabolic states, severe illness, after surgery, in non-insulin-dependent diabetes, burns, cancer, children with chronic renal failure (urine), diabetic retinopathy (humor), children with central nervous system tumors (cerebrospinal fluid) and in asthma. In synovial fluid of patients with osteoarthritis and rheumatoid arthritis the level of IGFBP-3 protease activty is lower than in healthy persons. Also, in interstitial fluid of patients with psoriasis, the IGFBP-3 protease activity is reduced, compared to healthy skin interstitial fluid (10 - 15, 19).In breast cancer an increased IGFBP-3 proteolysis and significant decrease of the protease activity has been observed after therapy with megestrol acetate (16 - 18). Also in patients with reduced tumor burden upon treatment with tamoxifen, a significant decrease of protease activity was observed.In a study the |
|---|
| Size | n/a |
|---|
| Concentration | n/a |
|---|
| Applications | n/a |
|---|
| Other Names | n/a |
|---|
| Gene, Accession, CAS # | n/a |
|---|
| Catalog # | hBP3ALICIA |
|---|
| Price | |
|---|
| Order / More Info | Functional IGFBP-3 ALICIA from IMMUNOLOGICAL & BIOCHEMICAL TESTSYSTEMS GmbH |
|---|
| Product Specific References | n/a |
|---|
| 产品资料 |
|
|