Introduction
Omentin is a newly identified secretary protein that is highly and selectively expressed in visceral adipose tissue relative to subcutaneous adipose tissue. Omentin has been identified in other tissues at lower expression levels and named intelectin, intestinal lactoferrin receptor, or endothelial lectin. It is expressed in intestinal paneth cells, endothelial cells and visceral adipose stromal -vascular cells. In vitro studies have shown that omentin increases insulin signal transduction by activating the protein kinase Akt/protein kinase B and enhancing insulin-stimulated glucose transport in isolated human adipocytes. Thus, omentin may play a paracrine or endocrine role in modulating insulin sensitivity.
The expression of omentin 1 and its homolog omentin 2 [intelectin-2] has been shown to be decreased with obesity. Omentin 1 is the major circulating form and its plasma levels are decreased in obesity. In other tissues omentin 1 is expressed at lower levels and has originally been shown to be involved in body defense by binding to galactofuranoses on bacteria.
A homolog of omentin has been identified that shares 83% amino acid identity with omentin/intelectin and will be referred to as omentin 2. The two omentin genes, omentin1 and omentin 2, are located adjacent to each other in the 1q22-q23 chromosomal region, which has been previously linked to type 2 diabetes in several populations.
Product Features
- Strip plates and additional reagents allow for use in multiple experiments
- Quantitative protein detection
- Establishes normal range
- The best products for confirmation of antibody array data
Application Notes
Kit Components
- Pre-Coated 96-well Strip Microplate
- Wash Buffer
- Standard Peptide
- Assay Diluent(s)
- Biotinylated Peptide
- HRP-Streptavidin
- TMB One-Step Substrate
- Stop Solution
- Assay Diagram
- Positive Control Sample
- Capture Antibody
- User Manual
Other Materials Required
- Distilled or deionized water
- Precision pipettes to deliver 2 µl to 1 ml volumes
- Adjustable 1-25 ml pipettes for reagent preparation
- 100 ml and 1 liter graduated cylinders
- Tubes to prepare standard and sample dilutions
- Orbital shaker
- Aluminum foil
- Saran Wrap
- Absorbent paper
- Microplate reader capable of measuring absorbance at 450nm
- SigmaPlot software (or other software that can perform four-parameter logistic regression models)
Protocol Outline
- Prepare all reagents, samples and standards as instructed.
- Add 100 µl detection antibody to each well.
- Incubate 1.5 h at RT or O/N at 4°C.
- Add 100 µl standard or sample to each well.
- Incubate 2.5 h at RT.
- Add 100 µl prepared streptavidin solution.
- Incubate 45 min at RT.
- Add 100 µl TMB One-Step Substrate Reagent to each well.
- Incubate 30 min at RT.
- Add 50 µl Stop Solution to each well.
- Read plate at 450 nm immediately.
Storage/Stability
Standard, Biotinylated Omentin peptide, and Positive Control should be stored at -20°C after arrival. Avoid multiple freeze-thaws. The remaining kit components may be stored at 4°C. Opened Microplate Wells and antibody (Item N) may be stored for up to 1 month at 2° to 8°C. Return unused wells to the pouch containing desiccant pack and reseal along entire edge.
