IGFBP-3 Total Human ELISA

Insulin-like growth factors (IGF)-I and -II are bound to specific binding proteins (IGFBPs) in the circulation. To date, at least six binding proteins can be distinguished on the basis of their amino acid sequence. They are designated as IGFBP-1, IGFBP-2 to IGPBP-6. Lately the discovery of a new IGFBP-7 has been discussed.

The predominating IGFBP in blood is IGFBP-3, which largely determines the total IGF-I and IGF-II concentration. In contrast to the other binding proteins, IGFBP-3 has the unique property to associate with an acid-labile non-binding subunit (ALS) after binding of either IGF-I or IGF-II. Most of the IGFBP-3 in plasma is present as the high molecular weight ternary complex, however, small amounts of free IGFBP-3 are also found. The development of specific immunoassays for IGFBP-3, recognizing the complete high molecular weight complex, provided new in-sights into ternary complex regulation. Several factors besides GH influence IGFBP-3 levels: age including sexual development, nutrition, hypothyroidism, diabetes mellitus, liver function and kidney function.

Measurement over 24 hours revealed constant circadian levels.

Features

• European Union: for in vitro diagnostic use
• Rest of the world: for research use only!
• Quantitative determination of IGFBP-3 without sample pretreatment
• Inter-Assay variation of 6.30% and Intra-Assay variation of 4.51%
• Sensitivity of 0.1 ng/ml
• Measures growth hormone (GH)-dependent IGFBP-3 Bindingprotein
• 2 Control Sera are provided for quality control purposes according GLP
• Stable serum levels due to absence of circadian variation
• Integrates the GH secretory state over days
• A single measurement is highly informative for diagnosis of GH deficiency or GH excess
• Ideal for the diagnosis of GH-deficiency in young children
• Small sample requirement, thus ideal for pediatric patients.

Research topic

Growth hormone and factor-related products