Laser Light Activation
Laser Light Activation - Related Videos
03:19
Inactivation of Bacteria Using Light-Activated Flavin Mononucleotide
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2025
Source: Cheng, C., et al. Inactivation of Pathogens via Visible-Light Photolysis of Riboflavin-5′-Phosphate. J. Vis. Exp. (2022)This video demonstrates a method for evaluating the phototoxic effects of flavin mononucleotide (FMN) on pathogenic bacteria. Bacterial cultures are exposed to increasing concentrations of FMN and illuminated with visible light to generate reactive oxygen species (ROS) that damage cellular components. The surviving bacteria are then quantified to assess the...
06:32
A Chitosan Based, Laser Activated Thin Film Surgical Adhesive, 'SurgiLux': Preparation and Demonstration
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Cited by 32 •
2012
The fabrication of a novel, flexible thin film surgical adhesive from FDA approved ingredients, chitosan and indocyanine green is described. Bonding of this adhesive to collagenous tissue through a simple activation process with a low-powered infra-red laser is demonstrated.
07:07
Optogenetic Perturbation of Neural Activity with Laser Illumination in Semi-intact Drosophila Larvae in Motion
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Cited by 13 •
2013
Here we describe a protocol for optogenetic manipulation of motoneuronal activity while monitoring changes in motor output (muscle contraction) in semi-intact Drosophila larvae using lasers within a conventional confocal microscope. This technique enables researchers to achieve local perturbation of neural activity in a few neuromeres to elucidate the dynamics of motor circuits.
02:59
Light-Activated Treatment of Bacterial Biofilms Using a Photosensitizer Precursor
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2026
Source: Zhao, K., et al. An In Vitro Model to Study the Effect of 5-Aminolevulinic Acid-mediated Photodynamic Therapy on Staphylococcus aureus Biofilm. J. Vis. Exp. (2018)The video demonstrates a photodynamic therapy protocol to assess antibacterial effects on Gram-positive bacterial biofilms. Biofilms are divided into four groups: two receive a photosensitizer precursor, and two receive a buffer. All are incubated in the dark, followed by red light exposure to one precursor-treated group and...
11:47
Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments
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Cited by 13 •
2013
White light microscope interferometry is an optical, noncontact and quick method for measuring the topography of surfaces. It is shown how the method can be applied toward mechanical wear analysis, where wear scars on tribological test samples are analyzed; and in materials science to determine ion beam sputtering or laser ablation volumes and depths.
FAQs
Laser wavelength determines which chromophore, meaning a light-absorbing molecule, receives the photon energy. In a medical target, that absorption can initiate different downstream effects depending on the material or tissue response. Matching the wavelength to the relevant chromophore therefore helps direct activation toward the intended target rather than treating all nearby structures as equally responsive.
The activated response can follow more than one pathway. Energy transfer may generate reactive oxygen species, while other settings or target properties may produce localized heating or molecular changes. These mechanisms are not interchangeable: the selected wavelength, intensity, exposure time, and tissue properties influence which effect dominates and therefore shape the expected biological outcome.
Selectivity depends on controlling both the laser and the tissue environment. Wavelength identifies the absorbing target, whereas intensity and exposure time influence how much energy is delivered. Tissue properties further modify the response. Coordinating these variables can concentrate the intended effect and limit unwanted changes in surrounding structures, an important consideration in medical treatment design.
A practical activation protocol begins by identifying the target and the desired response, then choosing laser settings that fit that goal. Wavelength, intensity, and exposure time must be controlled while accounting for tissue properties. This structured adjustment links the delivered irradiation to the intended chemical, physical, or biological effect and supports more selective treatment.
In photodynamic therapy, irradiation can activate a photosensitizing agent, with reactive oxygen species providing a possible treatment mechanism. In selective tissue ablation, the relevant response is used to remove or alter targeted tissue. These applications illustrate why activation parameters must be matched to the intended effect rather than applied uniformly across different medical targets.
Medical uses also include targeted drug release and light-based diagnosis. In drug release, laser-triggered molecular or physical changes can help control when a drug becomes available. Diagnostic approaches use light-induced responses to obtain information from a target. In both cases, wavelength-specific activation connects the optical input with a defined medical or investigative purpose.