A sandwich ELISA measures antigen between two layers of antibodies (capture and detection antibody). The target antigen must contain at least two antigenic sites capable of binding to antibodies. In the sandwich ELISA system, monoclonal or polyclonal antibodies can be used as capture and detection antibodies.
Monoclonal antibodies recognize a single epitope allowing small antigenic differences to be measured. Polyclonals are often used to capture antibodies to remove as much of the antigen as possible. bdnf elisa kit is also one of the best kits available online.
Sandwich ELISA eliminates the sample cleaning step before analysis and increases sensitivity (2-5 times more sensitive than direct or indirect).
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The sandwich ELISA procedure may be difficult to optimize and the tested paired antibody must be used. This ensures that the antibody recognizes a different epitope on the target protein and does not interfere with the binding of other antibodies.
BDNF (Brain Neurotrophic Factor) is a member of the neurotrophin growth factor family, which includes nerve growth factors. BDNF is expressed as a proprotein that cleaves to form mature BDNF (residue 129-247).
This test measures mature BDNF. The mature protein sequence of BDNF is identical in humans, mice, rats, and many other species. BDNF binds to at least 2 receptors: TrkB and LNGFR.
Radish peroxidase (HRP) and alkaline phosphatase (ALP) are the two enzymes most commonly used for detection in ELISA assays. Note that some biologics have high endogenous enzyme activity (such as high ALP in alveolar cells, high peroxidase in red blood cells), which can generate non-specific signals.
If necessary, perform additional blocking treatment with levamisole (for ALP) or 0.3% H2O2 in methanol (for peroxidase).