Quantitative mass spectrometric immunoassay of insulin like growth factor 1.
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.
Nelson
Randall W
RW
Intrinsic Bioprobes, Inc, Tempe, Arizona 85281, USA. rnelson@intrinsicbio.com
Nedelkov
Dobrin
D
Tubbs
Kemmons A
KA
Kiernan
Urban A
UA
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
D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II