Human IGF-I ELISA kit is a reliable quantitative procedure for measuring insulin like growth factor I (IGFI, IGF-I) in human serum and plasma. This assay has a minimum sensitivity detection limit of 0.09 ng/ml.


Insulin like growth factor I (IGFI, IGF-I) has a molecular weight of 7649 daltons and is identical with Somatomedin C (Sm-C). One of its main function is to regulate growth hormone (GH) and nutrition, even though it is produced by specific tissues it can be affected by a multitude of peptide growth factors and tropic hormones. IGFs are known to avidly bind specific binding proteins which are called Insulin-like growth factor binding proteins (IGFBP), which is in contrast to many other peptide hormones. There are seven classes of IGFBPs that can bind either IGF-I or IGF-II with similar affinities, however, many of these show a preference for IGF-II.

This can cause a major problem when measuring human IGF-I due to the ability of IGFBP being able to interfere with the assay.  In the past various techniques have being applied in order to physically separate the IGF-I from its binding protein before carry out the assay such as solid-phase extraction, size exclusion chromatography under acidic conditions and acid-ethanol extraction. These methods are time consuming, inconvenient or give incomplete and non-reproducible recoveries.

To avoid all these difficulties, the following human IGF-I ELISA kit does not require any special sample preparation before measurement. It can also be used for the human serum or plasma in cerebrospinal fluid, conditioned media of cell lines or other body fluids. Due to many mammalian species having a high cross reactivity with human IGF-I this assay can also be used in cattle, primate, sheep, donkey, pig, guinea pig dog, rabbit and cat. However, the current assay procedure is not suitable for mouse, rat or chicken samples.


All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

  • Microtiter Plate: Coated with mouse anti IGF-I antigen. Wells are separately breakable.
  • Standards A-E: Concentrations 2, 5, 15, 30, 50 ng/mL, made from lyophilized, recombinant human IGF-I.
  • Control Serum 1 And Control Serum 2.
  • Antibody Conjugate: Goat biotinylated anti-hIGF-I antibody.
  • Enzyme Conjugate: HRP-labelled Streptavidin.
  • Sample Buffer.
  • Washing Buffer (20x Concentrated).
  • TMB Substrate (Tetramethylbencidine).
  • Stopping Solution: 0.2 M sulphuric acid.
  • Sealing Tape: To cover microtiter plate.
  • Instructions For Use.
  • Quality Certificate.


The minimum sensitivity detection limit of human insulin like growth factor I (IGF-I, IGFI) using current IGF-I ELISA kit was approximately 0.09 ng/ml. The dynamic range for this assay is 2.0 – 50.0 ng/ml.


– Insulin Like Growth Factor I (IGF-I): ELISA
– Specificity: Highly specific and does not cross react with IGF-II, insulin, c-peptide.
– Intra Assay Variability: 5.08 – 6.65%
– Inter Assay Variability: 5.53 – 6.56%
– Recovery And Accuracy: 85 – 102%


  1. Human conditions of insulin like growth factor I (IGF-I) deficiency. J Transl Med. (2012) 10: 224. Review. Puche J.E. and Castilla-Cortázar I.
  2. Insulin-like growth factor-I (IGF-I) and clinical nutrition. Clin Sci (Lond). (2013) 125 (6): 265-80. Review. Livingstone C.
  3. Essential roles of growth hormone (GH) and insulin-like growth factor-I (IGF-I) in the liver. Endocr J. (2012)59 (11): 955-62. Review. Takahashi Y.
  4. Autocrine production of IGF-I increases stem cell-mediated neuroprotection. Stem Cells. (2015) 33 (5): 1480-9. Lunn J.S., et al.


  • Full Name: IGF-I ELISA Kit
  • Reactivity: Human
  • Sample Type: Serum, Plasma
  • Sensitivity: 0.09 ng/ml



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