Fluorescence polarization immunoassay (FPIA) for quantification of small molecules (CAT#: STEM-MB-0174-WXH)

The basis of the assay is fluorescence anisotropy, also known as fluorescence polarization. If a fluorescent molecule is stationary and exposed to plane-polarized light, it will become excited and consequently emit radiation back to the polarized-plane. Typically, the rate at which a molecule rotates is indicative of its size. When a fluorescent-labelled molecule (tracer) binds to another molecule the rotational motion will change, resulting in an altered intensity of plane-polarized light, which results in altered fluorescence polarization. Fluorescence polarization immunoassays employ a fluorophore bound antigen that when bound to the antibody of interest, will increase fluorescence polarization. The change in polarization is proportional to the amount of antigen in sample, and is measured by a fluorescence polarization analyzer.

Quantification of small molecules in mixtures, including: pesticides, mycotoxins in food, pharmaceutical compounds in wastewater, metabolites in urine and serum indicative of drug use (cannabinoids, amphetamines, barbiturates, cocaine, benzodiazepines, methadone, opiates, and PCP), and various small molecule toxins. As well as with the analysis of hormone-receptor interactions.

1. A specific quantity of sample is added to reaction buffer.
2. Equilibrate at room temperature
3. The solution is evaluated in a fluorescence polarization analyzer to gather a baseline measurement.
4. A specific quantity of antigen conjugated with fluorophore is added to the solution.
5. Equilibrates.
6. The solution is evaluated again by the fluorescence polarization analyzer.
7. The fluorescence polarization value for the tracer containing solution is compared to the baseline and magnitude of difference is proportional to quantity of target analyte in sample.