Noncompetitive ELISA for human serum insulin-like growth factor-I
| Autor: | J. Mistry, Anastasia Diamandi, Phillip Lee, M. J. Khosravi |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Chromatography
biology medicine.diagnostic_test Growth factor medicine.medical_treatment Biochemistry (medical) Clinical Biochemistry Extraction (chemistry) Insulin-like growth factor-binding protein Immunoassay biology.protein medicine Centrifugation Sample preparation Antibody Quantitative analysis (chemistry) |
| Zdroj: | Clinical Chemistry. 42:1147-1154 |
| ISSN: | 1530-8561 0009-9147 |
| DOI: | 10.1093/clinchem/42.8.1147 |
| Popis: | Measurement of serum insulin-like growth factor I (IGF-I) is important in assessing the growth hormone/IGF axis. Competitive immunoassay methods for IGF-I are complicated by substantial interference from IGF-binding proteins (IGFBPs) due to the relatively low ratio of specific antibody to IGFBPs in the sample, even after standard acid-ethanol sample extraction. We report of development of a noncompetitive ELISA for human IGF-I that avoids this problem by utilizing excess amounts of capture and detection antibodies. Serum samples were prepared by using an abbreviated acid-ethanol extraction method. Neutralized supernatant was added to microwells coated with IGF-I capture antibody; horseradish peroxidase-labeled detection antibody was then added, incubated for 2 h, and then developed. Compared with the "gold standard" method of acid-column chromatography, the simplified acid-ethanol extraction yields a mean +/- SD recovery of 103% +/- 5.5% despite the presence of residual IGFBPs in the extracted sample. Comparisons with a centrifugal filtration sample extraction method are also shown. The ELISA is specific for IGF-I with an absolute sensitivity of 0.03 microgram/L and inter- and intraassay CVs of 3.9-8.8% and 2.6-6.7%, respectively. The availability of a rapid IGF-I ELISA combined with a simple and reliable sample preparation procedure should facilitate clinical and research studies of this important growth factor. |
| Databáze: | OpenAIRE |
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