SpecificationsSpecificationsAdditional InformationCatalog #38-KAPF1991SpeciesHumanRegulatory StatusResearch Use Only. Not for Use in Diagnostic Procedures.Product DistributionAvailable WorldwideRange0-40 pg/mLSensitivity1.9 pg/mLSizes96 WellsSample TypesSerumIncubation Time2 hr .inchour { display:none; } Incubation Time2 hr 40 minSample Size10µLInstructions for UseClick here to viewSafety Data SheetClick here to viewAdditional InformationAdditional InformationNearly all circulating 25-OH Vitamin D in serum is bound to Vitamin D Binding Protein (88%) and Albumin (12%). Vitamin D Binding Protein (DBP) is a major component of serum, with a concentration of 250-400 mg/L of serum. Only a small portion, about 2%, of the Vitamin D binding sites of DBP is occupied. A very small fraction, approximately 0.04% of the 25(OH)Vitamin D, circulates in the free, non-protein bound form (1). The concentration of DBP is not constant and can be influenced by factors including obesity (2) pregnancy (3), the use of oral contraceptives (4) and liver disease (5). Variations in the concentration of DBP in serum will affect the unbound fraction 25-OH Vitamin D. For thyroid and steroid hormones it has been shown that their in vivo physiological activity correlates better with the free, non-protein bound fraction, than with the total concentration of the hormone in plasma. In such conditions the measurement of the concentration of the free circulating hormone provides more physiologically relevant information. This notion is known as the “free hormone hypothesis” (6). Particularly in situations in which the level of binding proteins is elevated or decreased, the measurement of total circulating hormone may lead to a wrong diagnosis. The bioavailability of 25-OH Vitamin D may be more complex, since it is a precursor that is metabolized in the kidney to the active 1,25(OH)2 Vitamin D. However, literature data suggest a role for the measurement of free 25-OH Vitamin D (7-10). The 25-OH Free Vitamin D ELISA makes it possible to measure the concentration of freely circulating 25-OH Free Vitamin D ELISA in serum. ReferencesKane et al (2013) Vitamin D3 effects on lipids differ in statin and nonstatin treated humans: superiority of free 25-OH D levels in detecting relationships. J ClinEndocrinMetab. 98(11):4400-9.Product ReviewsProduct ReviewsWrite a ReviewOnly registered users can write reviews. Please, log in or registerRelated ProductsRelated ProductsTotal 25-OH Vitamin D ELISAAdd to CartRequest a QuoteQuote RequestProduct: Total 25-OH Vitamin D ELISACatalog#: 38-25DHU-E01Qty:Comments:First Name:Last Name:Company:Email:Phone:Billing AddressAddress:City:State:Country:United StatesCanadaGermanyZipcode:Telephone:Shipping AddressSame as Billing AddressAddress:City:State:Country:United StatesCanadaGermanyZipcode:Telephone:Submit a quoteCatalog Number38-25DHU-E01Sensitivity: 2.8 ng/mLRange: 10-180 ng/mLSample Types: SerumSample Size(s):50 µL Add to Compare Add to WishlistRat 25-OH Vitamin D ELISAAdd to CartRequest a QuoteQuote RequestProduct: Rat 25-OH Vitamin D ELISACatalog#: 38-25DRT-E01Qty:Comments:First Name:Last Name:Company:Email:Phone:Billing AddressAddress:City:State:Country:United StatesCanadaGermanyZipcode:Telephone:Shipping AddressSame as Billing AddressAddress:City:State:Country:United StatesCanadaGermanyZipcode:Telephone:Submit a quoteCatalog Number38-25DRT-E01Sensitivity: 2.81 ng/mlRange: 5.3-133.0 ng/mlSample Types: SerumSample Size(s):50 µL Add to Compare Add to Wishlist