Fluorometric Assay
Fluorometric Assay - Related Videos
05:29
Measuring Caspase Activity Using a Fluorometric Assay or Flow Cytometry
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Cited by 6 •
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The present protocol describes two methods to measure caspase activity through a fluorogenic substrate using flow cytometry or a spectrofluorometer.
08:05
Multiplexed Fluorometric ImmunoAssay Testing Methodology and Troubleshooting
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Using Luminex Corporation’s xMAP microsphere technology, we have developed the Multiplexed Fluorometric ImmunoAssay (MFIA) for serosurveillance of various laboratory animal species. The MFIA is a suspension microarray where antigen, tissue control or immunoglobulins are covalently linked to color-coded polystyrene microspheres. The MFIA testing method as well as various troubleshooting topics is addressed.
07:37
Click-Chemistry Based Fluorometric Assay for Apolipoprotein N-acyltransferase from Enzyme Characterization to High-Throughput Screening
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Cited by 2 •
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07:29
Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
0 Views •
Cited by 15 •
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We describe here a fluorometric cell-free biochemical assay for determination of HDL-lipid peroxidation. This rapid and reproducible assay can be used to determine HDL function in large scale studies and can contribute to our understanding of HDL function in human disease.
12:33
High-throughput Fluorometric Measurement of Potential Soil Extracellular Enzyme Activities
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Cited by 485 •
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To measure potential rates of soil extracellular enzyme activities, synthetic substrates that are bound to a fluorescent dye are added to soil samples. Enzyme activity is measured as the fluorescent dye is released from the substrate by an enzyme-catalyzed reaction, where higher fluorescence indicates more substrate degradation.
FAQs
The assay either detects a fluorescent molecule already present in the sample or uses a fluorophore linked to the target of interest. Light at one wavelength excites that fluorescent component, and the resulting emission is measured at a longer wavelength. This separation allows the instrument to distinguish emitted signal from the excitation light and relate signal intensity to analyte abundance.
Fluorometric assays separate the light used for excitation from the light released by the fluorescent component. Because emission occurs at a longer wavelength, the measurement can focus on the fluorescent response rather than the incoming excitation light. This optical distinction supports sensitive detection, which is especially useful when biological samples contain relatively small amounts of the substance being measured.
Signal intensity reflects analyte abundance only under controlled conditions. Consistent assay conditions help preserve the relationship between the amount of target present and the fluorescence measured by the instrument. If conditions vary between samples, differences in signal may be harder to interpret as differences in analyte level, reducing the reliability of comparisons across a biological experiment.
A typical measurement begins with a sample containing either the fluorescent analyte or a target associated with a fluorophore. The sample is exposed to the selected excitation wavelength, and the instrument records fluorescence emitted at a longer wavelength. The measured signal is then used to assess the amount of analyte under the controlled conditions established for the experiment.
In biology, these assays can measure enzyme activity, nucleic acids, proteins, metabolites, and cell viability. The same fluorescence-based readout therefore supports several types of questions, from monitoring biochemical activity to estimating cellular or molecular quantities. Selecting the relevant fluorescent molecule or target-linked fluorophore allows the measurement approach to be adapted to the substance under investigation.
Their sensitivity, compatibility with microplate readers, and ability to work with small sample volumes make fluorometric assays suitable for rapid analysis of many samples. A microplate format supports repeated measurements across an experiment, while fluorescence provides a quantitative signal for biological targets. These features are valuable when researchers need to compare numerous enzyme, nucleic-acid, protein, metabolite, or cell-viability measurements.