title: Quantitative mass spectrometric immunoassay of insulin like growth factor 1.
abstract: Reported in this work are the development of mass spectrometric immunoassay (MSIA) devices and methods for the qualitative analysis of IGF-1 and -2, and the rigorous quantification of IGF-1 from human plasma. A method involving addition of SDS in moderate concentration to unfractionated plasma for disrupting IGF/IGFBP complexes was initially developed. The method is suitable for the direct extraction of the IGFs and subsequent mass spectrometric analysis. Rat plasma, containing IGF-1 that is mass shifted from human IGF-1, was used as an internal reference standard (IRS) for the quantification of IGF-1 directly from human plasma. A standard curve with linear dynamic range of at least 2 orders of magnitude was constructed from serially diluted IGF-1 standards containing equal amounts of rat plasma. Using the standard curve, IGF-1 levels in plasma samples from eight individuals were determined. The limit of detection for the IGF-1 MSIA was also evaluated and established to be approximately 15 pM. The assay is rapid and can be performed in parallel via high-throughput robotics processing. Furthermore, the mass spectrometry aspect of the developed IGF-1 immunoassay offers a new dimension in the ongoing study of IGF-1 and related diseases.
authors.affiliation: Intrinsic Bioprobes, Inc, Tempe, Arizona 85281, USA. rnelson@intrinsicbio.com
authors.forename: Randall W
authors.initials: RW
authors.lastname: Nelson
authors.forename: Dobrin
authors.initials: D
authors.lastname: Nedelkov
authors.forename: Kemmons A
authors.initials: KA
authors.lastname: Tubbs
authors.forename: Urban A
authors.initials: UA
authors.lastname: Kiernan
mesh_terms: D000818:Animals; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007335:Insulin-Like Growth Factor II / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D051381:Rats
chemical_list: D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II