Biomaterial Database

Direct detection of insulin-like growth factor II (IGF-II) by chemiluminescence without interference by IGF binding proteins. 1994

D D De León, and C Terry, and S P Nissley

National Institutes of Health, National Cancer Institute, Metabolism Branch, Bethesda, MD 20892.

A dot blot method for the detection of picogram quantities of human and rat insulin-like growth factor II (IGF-II) in serum-free conditioned media is described. The crossreactivity of human recombinant IGF-I in the assay was < 10%. None of the IGF binding proteins (IGFBP 1-6) diminished the IGF-II signal. In contrast, significant interference by the IGFBPs was observed when the same concentrations of IGFBPs and 125I-IGF-II were used in a radioimmunoassay which utilized the same antibody. Why IGF-II is detected in the dot blot assay without IGFBP interference is not understood. We speculate that the conformation of the IGF-II/binding protein complex may be altered by binding to the nitrocellulose, exposing the IGF-II epitope that is recognized by the antibody. IGF-II was detected in 1 microliter of serum-free conditioned media from BRL 3A cells (which secrete IGF-II) while no signal was generated by 50 microliters of BRL 3A2 conditioned media (which do not secrete IGF-II). In summary, this method is ideal for screening cells in serum free-culture for production of IGF-II without the need for separation of IGF-II from cell derived IGFBPs.

UI	MeSH Term	Description	Entries
D007335	Insulin-Like Growth Factor II	A well-characterized neutral peptide believed to be secreted by the LIVER and to circulate in the BLOOD. It has growth-regulating, insulin-like and mitogenic activities. The growth factor has a major, but not absolute, dependence on SOMATOTROPIN. It is believed to be a major fetal growth factor in contrast to INSULIN-LIKE GROWTH FACTOR I, which is a major growth factor in adults.	IGF-II,Multiplication-Stimulating Activity,Somatomedin MSA,IGF-2,Insulin Like Growth Factor II,Insulin-Like Somatomedin Peptide II,Multiplication-Stimulating Factor,Somatomedin A,Factor, Multiplication-Stimulating,Insulin Like Somatomedin Peptide II,Multiplication Stimulating Activity,Multiplication Stimulating Factor
D008163	Luminescent Measurements	Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.	Bioluminescence Measurements,Bioluminescent Assays,Bioluminescent Measurements,Chemiluminescence Measurements,Chemiluminescent Assays,Chemiluminescent Measurements,Chemoluminescence Measurements,Luminescence Measurements,Luminescent Assays,Luminescent Techniques,Phosphorescence Measurements,Phosphorescent Assays,Phosphorescent Measurements,Assay, Bioluminescent,Assay, Chemiluminescent,Assay, Luminescent,Assay, Phosphorescent,Assays, Bioluminescent,Assays, Chemiluminescent,Assays, Luminescent,Assays, Phosphorescent,Bioluminescence Measurement,Bioluminescent Assay,Bioluminescent Measurement,Chemiluminescence Measurement,Chemiluminescent Assay,Chemiluminescent Measurement,Chemoluminescence Measurement,Luminescence Measurement,Luminescent Assay,Luminescent Measurement,Luminescent Technique,Measurement, Bioluminescence,Measurement, Bioluminescent,Measurement, Chemiluminescence,Measurement, Chemiluminescent,Measurement, Chemoluminescence,Measurement, Luminescence,Measurement, Luminescent,Measurement, Phosphorescence,Measurement, Phosphorescent,Measurements, Bioluminescence,Measurements, Bioluminescent,Measurements, Chemiluminescence,Measurements, Chemiluminescent,Measurements, Chemoluminescence,Measurements, Luminescence,Measurements, Luminescent,Measurements, Phosphorescence,Measurements, Phosphorescent,Phosphorescence Measurement,Phosphorescent Assay,Phosphorescent Measurement,Technique, Luminescent,Techniques, Luminescent
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001345	Autoradiography	The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)	Radioautography
D013002	Somatomedins	Insulin-like polypeptides made by the liver and some fibroblasts and released into the blood when stimulated by SOMATOTROPIN. They cause sulfate incorporation into collagen, RNA, and DNA synthesis, which are prerequisites to cell division and growth of the organism.	Sulfation Factor,Somatomedin,Factor, Sulfation
D015151	Immunoblotting	Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.	Dot Immunoblotting,Electroimmunoblotting,Immunoelectroblotting,Reverse Immunoblotting,Immunoblotting, Dot,Immunoblotting, Reverse,Dot Immunoblottings,Electroimmunoblottings,Immunoblottings,Immunoblottings, Dot,Immunoblottings, Reverse,Immunoelectroblottings,Reverse Immunoblottings