Glucagon-like peptide-1 (GLP-1) is a highly conserved amino-acid-long peptide hormone among mammals and mainly secreted from the intestinal L-cells and the CNS. Functionally, GLP-1 plays an important role in energy homeostasis and nutrient absorption. The initial product GLP-1 (1–37) is susceptible to amidation and proteolytic cleavage, which gives rise to the two truncated and equipotent biologically active forms, GLP-1 (7–36) amide and GLP-1 (7–37). Then, the active forms of GLP-1 are extremely susceptible to the catalytic activity of the proteolytic enzyme dipeptidyl peptidase-4 (DPP-4), resulting in the abundant inactivated GLP-1 (9–36) amide constituting 60–80% of total GLP-1 in circulation. This kit measures total GLP-1 including full length GLP-1 (1–37), the active (7-36) and inactive (9-36) forms of GLP-1.

• 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

• Pre-Coated 96-well Strip Microplate
• Wash Buffer
• Lyophilized Standard
• Capture Antibody
• Assay Diluent
• Biotinylated Peptide
• HRP-Streptavidin
• Positive Control
• TMB One-Step Substrate Reagent
• Stop Solution

• Microplate reader capable of measuring absorbance at 450 nm
• 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
• Absorbent paper
• Distilled or deionized water
• Software which can perform four-parameter logistic regression models
• Tubes to prepare standard or sample dilutions
• Orbital shaker
• Aluminum foil
• Plastic wrap

1. Prepare all reagents, samples and standards as instructed.
2. Add 100 µL Capture Antibody to each well. Incubate 1.5 hours at room temperature or overnight at 4°C.
3. Add 100 µL standard or sample to each well. Incubate 2.5 hours at room temperature or overnight at 4°C.
4. Add 100 µL prepared Streptavidin solution. Incubate 45 minutes at room temperature.
5. Add 100 µL TMB One-Step Substrate Reagent to each well. Incubate 30 minutes at room temperature.
6. Add 50 µL Stop Solution to each well. Read at 450 nm immediately.

The entire kit may be stored at -20°C to -80°C for up to 6 months from the date of shipment. For extended storage, it is recommended to store it at -80°C. Avoid repeated freeze-thaw cycles.