Doubly-resonant Cars
Doubly-resonant Cars - Related Videos
12:56
Differential Imaging of Biological Structures with Doubly-resonant Coherent Anti-stokes Raman Scattering (CARS)
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Cited by 2 •
2010
A combination of three single wavelength short-pulsed lasers is used to generate coherent anti-Stokes Raman scattering (CARS) and doubly-resonant CARS (DR-CARS). The difference between these signals provides enhanced sensitivity for otherwise difficult to detect coherent Raman signals, enabling imaging of weak Raman scatterers.
02:55
Genetically Modifying CAR T Cells Using a CRISPR-Cas9 System
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2025
The video outlines a process for creating genetically modified CAR T cells through the CRISPR-Cas9 System. Infecting T cells with CRISPR and CAR lentiviruses results in modifications to the target gene and the synthesis of a chimeric antigen receptor or CAR, ultimately leading to the formation of genetically modified CAR T cells.
03:32
A Technique for the Generation of Antigen-Specific CAR T Cells
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2025
This video demonstrates a technique for generating antigen-specific chimeric antigen receptor (CAR) T cells through retroviral transduction. Activated murine CD8+ T cells are added to a microwell plate coated with recombinant fibronectin fragments. Retroviral vectors containing transgenic RNA encoding an antigen-specific chimeric antigen receptor (CAR) are then introduced, and the plate is centrifuged to facilitate transduction. After incubation, the transduced cells express antigen-specific...
02:52
Resonance
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2020
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N-O and N=O bonds. If nitrite ions do indeed contain a single and a double bond, the two bond lengths are expected to be different. A double bond between two atoms is shorter (and stronger) than a single bond between the same two atoms. However, experiments show that both N–O bonds in NO2− have the same strength and length, and are identical in all other...
03:13
An In Vitro Assay to Assess CAR T Cell Cytotoxicity against Tumor Spheroids
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2025
This video demonstrates an in vitro assay evaluating the cytotoxic effects of CAR T cells on 3D tumor spheroids expressing fluorescent proteins. This assessment utilizes the Annexin V red fluorescent probe, which binds to exposed phosphatidylserine residues on the outer leaflet of apoptotic cancer cells after interactions with CAR T cells. The red fluorescence emitted by the probe aids in distinguishing these cells from healthy ones emitting green fluorescence.
FAQs
Signal enhancement depends on satisfying two resonance conditions at once. The pump-Stokes frequency difference is adjusted to a molecular vibration, while the resulting anti-Stokes field is positioned near an electronic transition. These coupled resonances strengthen the coherent Raman response, producing greater chemical contrast than would result from relying on vibrational matching alone.
A vibrationally resonant measurement uses frequency matching to target a molecular vibration, whereas Doubly-resonant CARS adds a second condition involving an electronic transition. The additional electronic resonance can increase the generated coherent Raman field. This distinction matters when stronger molecular contrast is needed to visualize chemically varied biological material.
Careful control helps preserve the chemical signal while limiting unwanted fluorescence and photodamage. Excitation conditions determine how effectively the vibrational and electronic resonances are coupled, but excessive or poorly controlled excitation can compromise biological samples. Managing these conditions is therefore important for obtaining interpretable images of cells and tissues.
The pump and Stokes beams are selected so their frequency difference matches the molecular vibration being investigated. The experiment then uses the generated anti-Stokes field under conditions that bring it near an electronic transition. In microscopy, the resulting coherent Raman response can be collected across the sample to generate chemically informative images.
The method can provide label-free chemical contrast for lipids, proteins, and other molecular components in cells and tissues. Because signal generation is linked to molecular resonances, different biological constituents can contribute distinct contrast without requiring an added label. This makes the approach useful for examining how molecular components are arranged within biological samples.
Doubly-resonant CARS can support investigations of cellular organization, metabolism, and disease-related molecular changes. Its enhanced chemical contrast helps connect image features with the distribution of cellular constituents, while the label-free format supports direct examination of cells and tissues. Researchers can therefore use it to compare molecular patterns associated with normal and altered biological states.