Fluorescence Assay Quantification
Fluorescence Assay Quantification - Related Videos
06:45
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Cited by 8 •
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03:08
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06:55
Simple Bulk Readout of Digital Nucleic Acid Quantification Assays
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Cited by 5 •
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We describe an endpoint digital assay for quantifying nucleic acids with a simplified (analog) readout. We measure bulk fluorescence of droplet-based digital assays using a standard qPCR machine rather than specialized instrumentation and confirm our results by microscopy.
07:35
Preparation, Imaging, and Quantification of Bacterial Surface Motility Assays
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Cited by 68 •
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Swarming motility is influenced by physical and environmental factors. We describe a two-phase protocol and guidelines to circumvent the challenges commonly associated with swarm assay preparation and data collection. A macroscopic imaging technique is employed to obtain detailed information on swarm behavior that is not provided by current analysis techniques.
12:22
Automated Quantification of Synaptic Fluorescence in C. elegans
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Cited by 5 •
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The abundance of neurotransmitter receptors clustered at synapses strongly influences synaptic strength. This method quantifies fluorescently-labeled neurotransmitter receptors in three dimensions with single-synapse resolution in C. elegans, allowing hundreds of synapses to be rapidly characterized within a single sample without distortions introduced by z-plane projection.
FAQs
The fluorophore absorbs energy from the excitation light and then releases part of that energy as emitted light at a longer wavelength. This separation helps the instrument distinguish the biological signal from the incoming excitation beam. Measuring the resulting emission allows fluorescence assay quantification to connect optical behavior with the presence or activity of a target.
Background fluorescence adds signal that does not originate from the intended biological target, while quenching reduces the fluorescence produced by the fluorophore. Both effects can distort the relationship between measured intensity and target amount or activity. Controlling these factors is therefore essential for accurate comparisons, reliable calibration, and reproducible results across assay conditions.
A standard curve links known standard concentrations with their measured fluorescence signals. The signal from an unknown sample can then be compared with this relationship to estimate concentration. When the assay measures enzyme or cellular function instead of amount, fluorescence may instead support a relative activity comparison, provided the assay conditions remain consistent.
A plate reader or fluorometer supplies excitation light and measures the resulting emission signal. In a basic workflow, samples are prepared with the relevant fluorophore or fluorescent assay system, the instrument records fluorescence, and calibrated standards provide a reference for interpreting the readings. The selected instrument supports either individual measurements or larger sample sets.
This approach is useful when investigators need sensitive measurements of proteins, nucleic acids, enzymes, or cell-associated components. It can report target concentration or relative biological activity, depending on how the assay is calibrated. Applications include protein and nucleic acid assays, enzyme studies, cell-based experiments, and high-throughput screening of many samples.
Fluorescence measurements can be collected across many assay samples with a plate reader, allowing researchers to compare target-associated signals efficiently. Standard-based calibration supports concentration estimates, whereas consistent conditions can support relative activity measurements. Managing background fluorescence and quenching is especially important in screening because signal distortions could affect comparisons among large numbers of samples.