USP ELISA Kits are immunoassays designed for the quantitative measurement of specific proteins, peptides, or small molecules in biological samples using the principles of enzyme-linked immunosorbent assay (ELISA). These kits are developed and validated by the United States Pharmacopeia (USP) for ensuring the quality, purity, strength, and consistency of pharmaceutical products and raw materials.
Key Components of USP ELISA Kits:
- Microplate: Usually a 96-well plate coated with an antibody specific to the target analyte.
- Standards: Known concentrations of the target analyte used to generate a standard curve for quantification.
- Detection Antibody: An antibody that binds to the target analyte, often conjugated to an enzyme such as horseradish peroxidase (HRP) or alkaline phosphatase (AP).
- Substrate: A chromogenic or chemiluminescent substrate that reacts with the enzyme to produce a measurable signal, proportional to the amount of analyte.
- Buffers: Solutions for washing, blocking, and assay diluents to optimize the assay conditions.
Procedure:
- Coating: The microplate wells are pre-coated with a capture antibody specific to the target analyte.
- Sample Addition: Samples and standards are added to the wells, where the analyte binds to the capture antibody.
- Detection: A detection antibody, linked to an enzyme, is added and binds to the analyte, forming a sandwich complex.
- Signal Development: The substrate is added, and the enzyme catalyzes a reaction that produces a detectable signal.
- Measurement: The signal intensity is measured using a spectrophotometer or luminometer, depending on the type of substrate used.
- Quantification: The analyte concentration in the samples is determined by comparing the sample signal to the standard curve.
Applications:
- Pharmaceutical Testing: Quantifying specific proteins or contaminants in drug formulations.
- Clinical Diagnostics: Measuring biomarkers for disease diagnosis and monitoring.
- Biological Research: Studying protein expression, signaling pathways, and immune responses.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|