Quantification of insulin-like growth factor I (IGF-I) without interference by IGF binding proteins.

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.

journal_name

Endocrinology

journal_title

Endocrinology

authors

De León DD,Asmerom Y

doi

10.1210/endo.138.5.5237

subject

Has Abstract

pub_date

1997-05-01 00:00:00

pages

2199-202

issue

5

eissn

0013-7227

issn

1945-7170

journal_volume

138

pub_type

杂志文章