Label-free Measurement
Label-free Measurement - Related Videos
09:19
Simultaneous Label-Free Autofluorescence Multi-Harmonic Microscopy
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Cited by 3 •
2025
This protocol presents a step-by-step guide for the Simultaneous Label-free Autofluorescence Multi-harmonic (SLAM) microscopic technique, including details on how to generate the laser light source, prepare a tissue sample, conduct imaging, and analyze the data. SLAM advances nonlinear microscopy by measuring four complementary label-free contrasts to investigate the tissue microenvironment.
06:56
Measuring Exocytosis in Neurons Using FM Labeling
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Cited by 7 •
2006
The ability to measure the kinetics of vesicle release can help provide insight into some of the basics of neurotransmission. Here we used real-time imaging of vesicles labeled with the red fluorescent dye FM 4-64 to measure the rate of presynaptic vesicle release in hippocampal neuronal cultures.
03:59
Bromodeoxyuridine Pulse Labelling Assay: A Technique to Measure Cell Proliferation
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2023
The video describes the stepwise pulse labeling assay of mammalian cells with bromodeoxyuridine (BrdU) for measuring cell proliferation. The BrdU uptake permits the temporal tracking of cells that were in the synthesis phase at a specific point in time, without requiring the cells to be synchronized.
11:23
Measuring Cell Cycle Progression Kinetics with Metabolic Labeling and Flow Cytometry
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Cited by 13 •
2012
Tracking subtle changes in the progression and kinetics of cell cycle stages can be accomplished by use of a combination of metabolic labeling of nucleic acids with BrdU and total genomic DNA staining via Propidium Iodide. This method avoids the need of chemical synchronization of cycling cells, thereby preventing the introduction of non-specific DNA damage, which in turn affects cell cycle progression.
10:13
Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding
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Cited by 11 •
2017
Guanosine triphosphate (GTP) binding is one of the earliest events in G-Protein-Coupled Receptor (GPCR) activation. This protocol describes how to pharmacologically characterize specific GPCR-ligand interactions by monitoring the binding of the radio-labeled GTP analog, [35S]guanosine-5'-O-(3-thio)triphosphate ([35S]GTPγS), in response to a ligand of interest.
FAQs
Intrinsic signals translate biological events into measurable physical changes. Mass, refractive index, impedance, optical scattering, and mechanical behavior can shift when cells, molecules, or tissues interact with a sensor or change state. Tracking these signals allows investigators to follow processes such as binding, growth, adhesion, viability, or differentiation without adding a detection tag.
Removing tags helps preserve the native properties of the sample and reduces sample preparation. This can limit perturbations introduced by labeling and simplify analysis, particularly when measurements must continue over time. The resulting data can support observations of biological behavior under conditions closer to the sample’s unmodified state.
Each signal emphasizes a different aspect of sample behavior. Mass and refractive index can indicate molecular or cellular interactions, while impedance, optical scattering, and mechanical behavior provide other measures of biological change. Matching the measurable signal to the process of interest helps distinguish binding, cell-state changes, or tissue behavior in bioengineering studies.
Because measurements can follow intrinsic changes as they occur, investigators can monitor biological processes repeatedly rather than relying only on a final endpoint. This supports real-time observation and longitudinal studies of cell growth, viability, adhesion, and differentiation. Reduced preparation also contributes to higher throughput when many samples or conditions must be compared.
A study generally places cells, molecules, or tissues in contact with a suitable sensor or monitors their biological changes, then records the resulting intrinsic physical signal. Investigators select the signal relevant to the target process and track its change over time. The measurements can then characterize interactions, cellular behavior, or tissue responses.
It is particularly useful when researchers need to monitor living or engineered biological systems while minimizing preparation and label-related perturbation. Applications described for the approach include diagnostic platforms, drug screening, cell-state monitoring, and evaluation of engineered tissues. Its capacity for real-time and longitudinal analysis can provide information that endpoint measurements may not capture.