Quantitative, Competitive ELISA for Detection of Soluble Factors in a Variety of Species
RayBio® kits utilize the principle of Competitive Enzyme Immunoassay (EIA), in which the target protein and a biotin-conjugated peptide bind competitively to a capture antibody. This assay requires only a single antibody, generating signal output by interaction of the biotinylated competitor with streptavidin-HRP. Thus, the EIA kits are particularly useful for detecting peptide hormones and other molecules for which no antibody pair exists, or for which antibody pairs cannot be developed.
Compare All ELISA SystemsBrowse EIA Kits
Another important advantage of the EIA format is broad-species reactivity. For each kit, a peptide derived from a high-homology region of the target protein sequence serves as both the standard and the biotin-labeled competitor. RayBio® EIA kits are validated for rat, mouse, and human samples and have expected reactivity with many other species.
- Excellent for follow up/confirmation of E-Series Array data
- Broad species reactivity
- Strip plate format minimizes waste
- Complete kit includes all necessary reagents
- Highly sensitive and specific
- Reproducible and reliable
- Optimized for serum, plasma, and cell culture medium
Contents of Kit
- 96-well strip plate (12x8)
- Wash Buffer Concentrate (20x)
- Standard Peptide
- Capture antibody
- Positive control
- Diluent Buffers
- Biotin-labeled peptide
- HRP-Streptavidin concentrate
- TMB One-Step Substrate Reagent
- Stop Solution
How It Works
The samples and standards, which are spiked with biotinylated peptide, are pipetted into the assay plate; the target protein and the labeled peptide interact competitively with the capture antibody. After washing, the bound biotin-peptide then interacts with streptavidin-HRP, producing a color development reaction. The intensity of colorimetric signal is directly proportional to the amount of biotin-peptide and inversely proportional to the amount of target protein in the samples.
- Detection of quantitative protein levels in biological fluids
- Validation of array results
- Validation of biomarker discovery studies
- Plum L, Lin HV, Dutia R, Tanaka J, Aizawa KS, et al. The Obesity Susceptibility Gene Carboxypeptidase E Links FoxO1 Signaling in Hypothalamic Pro–opiomelanocortin Neurons with Regulation of Food Intake. Nature Med. 2009;15(10):1195-1201. (Ghrelin EIA, EIA-GHR-1) | Full Text
- Hug C, Lodish HF. Visfatin: a new adipokine. Science. 2005; 307(5708):366-7.
- Kim MK. Crystal structure of visfatin/pre-B cell colony-enhancing factor 1/nicotinamide phosphoribosyltransferase, free and in complex with the anti-cancer agent FK-866. J Mol Biol. 2006; 362(1):66-77.
- Revollo, J.R., et al. The NAD biosynthesis pathway mediated by nicotinamide phosphoribosyltransferase regulates Sir2 activity in mammalian cells. J. Biol. Chem. 2004; 279: 50754-50763.
- Oh-I S, Shimizu H, Satoh T, et al. Identification of nesfatin-1 as a satiety molecule in the hypothalamus". Nature 2006; 443 (7112): 709-12.
- Zhang J, Ren P, Avsian-Kretchmer O, Luo C, Rauch R, Klein C, Hsueh A. Obestatin, a peptide encoded by the ghrelin gene, opposes ghrelin's effects on food intake. Science 2005; 310 (5750): 996-9.
- Cummings D, Weigle D, Frayo R, Breen P, Ma M, Dellinger E, Purnell J. Plasma ghrelin levels after diet-induced weight loss or gastric bypass surgery. N Engl J Med 2002; 346 (21): 1623-30.
- Tschöp M, Smiley DL, Heiman ML. Ghrelin induces adiposity in rodents. Nature 2002; 407 (6806): 908-913.9. Kojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature 1999; 402 (6762): 656-60.