Quantification of insulin-like growth factor I (IGF-I) without interference by IGF binding proteins.
Endocrinology
; 138(5): 2199-202, 1997 May.
Article
em En
| MEDLINE
| ID: mdl-9112420
ABSTRACT
A chemiluminescent dot blot assay has been developed by our laboratory for rapid determinations of IGF-I in serum-free conditioned media (CM) collected from cultured cells. In contrast to IGF-I radioimmunoassays (RIAs), the IGF binding proteins (IGFBPs) did not interfere with the dot blot assay and did not require the laborious (and sometimes ineffective) removal of IGFBPs. Although all six IGFBPs were shown to bind to 125I IGF-I, none interfered with IGF-I detection on nitrocellulose dot blots. In contrast, an RIA using the same Oncogene monoclonal antibody (clone 82-9A) showed interference by IGFBP-1, IGFBP-2, and IGFBP-4. The IGF-I dot blot assay was sensitive (0.125-8.0 ng IGF-I), specific (assay crossreactivity with IGF-II is less than 1%), and reproducible (intra-assay variance < or = 6%; inter-assay variance < 12%) when chemiluminescence was quantified by phosphorimager and Molecular Analyst software (BioRad). The apparent sensitivity of the enhanced chemiluminescence (ECL) reagent to serum, precludes the use of this assay for IGF-I determination in serum or in serum-containing media.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Crescimento Insulin-Like I
/
Técnicas de Imunoadsorção
/
Meios de Cultivo Condicionados
/
Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina
/
Medições Luminescentes
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Revista:
Endocrinology
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos