hreynolds at uh.edu
hreynolds at uh.edu
Fri Jun 14 13:06:07 EST 1996
DSL (Diagnostic Systems Laboratories, Inc.) is pleased to introduce the
NEW Non-Extraction IGF-I IRMA and ELISA kits for quantifying IGF-I in
serum and plasma without the necessity of performing time-consuming and
equipment-intensive extraction procedures. The Non-Extraction IGF-I
assay is 510(k) cleared for marketing for in vitro diagnostic use as an
aid in the diagnosis of growth-related disorders.
IGF-I is a 7.6 kDa, 70 amino acid peptide that mediates the actions of
growth hormone. It is secreted by the liver and several other tissues
and is postulated to have mitogenic and metabolic actions at or near the
sites of synthesis. IGF-I appears in the peripheral circulation
primarily in a high molecular weight complex with IGF-binding protein-3
and acid-labile subunit (ALS). A smaller proportion of IGF-I may
circulate in association with other IGF-binding proteins. Approximately
2-4% of the total IGF-I may circulate unbound.
The IGF-I assays are useful in the diagnosis of growth-related disorders.
Abnormally low IGF-I levels may be a diagnostic indicator of growth
hormone deficiency. Conversely, elevated IGF-I levels may be indicative
of growth hormone excess. Direct testing of growth hormone may be
clinically unreliable due to its episodic release from the pituitary and
relatively short half-life in the circulation, whereas IGF-I levels
remain relatively stable throughout the day.
Immunoassay of IGF-I may be complicated by the presence of the high
affinity binding proteins in the sample. Historically, it has been
necessary to separate the IGFs from the binding proteins prior to
assaying for IGF-I. The traditional extraction procedures, including
chromatography, multiple acidification and neutralization steps, and
centrifugation to prepare the samples are no longer required when using
the DSL Non-Extraction IGF-I assays. The specimens are simply diluted in
the sample diluent provided and allowed to equilibrate at room
temperature for 30 minutes.
The DSL assay kits utilize a two-site antibody system with highly
specific antibodies directed against the human insulin-like growth
factor-I peptide. No cross-reactivity with IGF-II is exhibited, and no
interference results from the addition of insulin, proinsulin, or growth
hormone at concentrations of 1 µg/tube.
The DSL ACTIVE Non-Extraction IGF-I IRMA is a 100 tube kit featuring the
convenience of an antibody-coated tube format and a total assay
incubation time of only 2 hours. The DSL ACTIVE Non-Extraction IGF-I
ELISA is a 96-well microtitre plate assay featuring a total assay
incubation time of 2.5 hours.
Both assays are calibrated using the World Health Organization
international reference preparation for IGF-I immunoassay (code 87/518).
The assays feature an extended standard range of 8 - 1000 ng/mL. The
absolute sensitivity of the IGF-I IRMA kit is 0.04 ng/mL, and the
absolute sensitivity of the ELISA is 0.03 ng/mL. Both kits include two
levels of controls.
In addition to the ACTIVE Non-Extraction IGF-I IRMA and ELISA kits, DSL
offers a full range of immunodiagnostic test kits and reagents for
studies related to disorders of the growth hormone-IGF axis, an extensive
line of assays for the studies of bone and mineral metabolism, a
complete line of assays for fertility and reproductive function, androgen
assessment, and more.
For more information regarding the ACTIVE Non-Extraction IGF-I IRMA and
ELISA kits (catalog numbers DSL-2800 and DSL-10-2800, respectively) as
well as other DSL products and services, contact the DSL Customer
Assistance Center in Webster, TX, USA by phone 800.231.7970 or
713.332.9678, by fax 713.338.1895, or by e-mail mktg at dslabs.com
Diagnostic Systems Laboratories
445 Medical Center Blvd.
Webster, TX 77598
More information about the Methods