Radioactive Substrate Detection
Radioactive Substrate Detection - Related Videos
04:25
Substrate Oxidation Assay in Cultured Cells: An In Vitro Assay to Quantify Substrate Oxidation in Cells by Measuring Radioactive Signals from Trapped CO2
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2025
This video demonstrates a quantification technique for CO2 released during substrate oxidation using 14C-radiolabeled substrates. The released 14CO2 is trapped in an alkaline solution and quantified by a scintillation counter. The oxidation of different substrates varies between tissues and reflects the pathophysiological condition of the tissue.
03:18
Radioactivity and Nuclear Equations
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2020
Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The nucleus of an atom is composed of protons and, except for hydrogen, neutrons. The number of protons in the nucleus is called the atomic number (Z) of the element, and the sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are isotopes of the same element. A nuclide of an element has a specific number of protons and...
17:38
Radioactive in situ Hybridization for Detecting Diverse Gene Expression Patterns in Tissue
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Cited by 21 •
2012
This protocol is successfully used to quantitatively detect levels and spatial patterns of mRNA expression in multiple tissue types across vertebrate species. The method can detect low abundance transcripts and allows processing of hundreds of slides simultaneously. We present this protocol using expression profiling of avian embryonic brain formation as an example.
02:48
Radioactive Decay and Radiometric Dating
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2020
Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time. The SI unit for activity is the becquerel, which is one disintegration per second. Another unit of activity is the...
11:13
Identification of Kinase-substrate Pairs Using High Throughput Screening
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Cited by 1 •
2015
Protein phosphorylation is a central feature of how cells interpret and respond to information in their extracellular milieu. Here, we present a high throughput screening protocol using kinases purified from mammalian cells to rapidly identify kinases that phosphorylate a substrate(s) of interest.
FAQs
The measurement follows the isotope-bearing portion of the molecule rather than merely detecting total material. If cells or enzymes transport, convert, or incorporate the labeled substrate, the resulting radioactive signal provides evidence that the substrate participated in a biological process. This distinction helps connect molecular presence with uptake, transformation, or incorporation into products.
Transport determines where the labeled molecule can be found, conversion changes its chemical form, and incorporation places isotope-labeled material into cellular products. Tracking these stages allows investigators to distinguish movement through a system from biochemical transformation or synthesis. In biology, that distinction helps connect a measured signal with a specific step in substrate handling.
Radioactive substrate detection may remain preferable when experiments require high sensitivity or direct evidence that a substrate was taken up and transformed. Nonradioactive approaches are increasingly available, so method selection can reflect the balance between an established radioactive signal and newer alternatives. The technique remains useful when subtle substrate handling must be measured reliably.
A typical workflow begins by exposing cells, tissues, or an enzyme system to a molecule labeled with a radioactive isotope. Investigators then measure emitted radiation with a scintillation counter when quantification is needed, or use autoradiography to localize the signal. The selected readout links substrate handling to either overall activity or spatial distribution.
An enzyme reaction can be followed by measuring how labeled substrate is converted into products, while pathway studies track the substrate through successive biochemical changes. Quantifying the associated radiation helps estimate metabolic activity or reaction progress. In this way, the method connects a measurable signal with enzyme function and the movement of substrates through cellular pathways.
Autoradiography provides spatial information by localizing radiation within a sample rather than reducing the result to a single overall measurement. When labeled substrate becomes part of newly synthesized molecules, the resulting pattern can show their distribution across cells or tissues. This makes the approach useful for linking biochemical synthesis with biological location.