Laser assisted microdissection

Laser assisted microdissection

Laser Assisted Microdissection (LAM) is a precise microsurgical technique used to isolate specific cells or regions of tissue from a heterogeneous sample under microscopic visualization. This method is widely used in molecular biology, genomics, and pathology for the analysis of DNA, RNA, and proteins from specific cell populations.

Principle

Laser Assisted Microdissection utilizes a focused laser beam to cut around the area of interest in a tissue section. The laser is typically a UV laser, which allows for precise cutting without damaging the surrounding tissue. The process is conducted under a microscope, allowing for high-resolution visualization and selection of the target area.

Equipment

The main components of a Laser Assisted Microdissection system include:

• A high-resolution microscope equipped with a digital camera for visualization and documentation.
• A UV laser source, often a nitrogen laser or a solid-state laser, capable of producing a focused beam for precise cutting.
• A computer system with specialized software for controlling the laser and capturing images.
• A stage for holding and moving the tissue sample.

Procedure

The procedure for Laser Assisted Microdissection involves several steps:

1. Sample Preparation: Tissue samples are typically fixed and embedded in a medium such as paraffin or frozen in cryostat sections. The sections are then mounted on specialized slides that are compatible with the laser system.
2. Staining: To enhance visualization, tissue sections may be stained using standard histological stains such as hematoxylin and eosin (H&E) or specific immunohistochemical stains.
3. Microscopic Visualization: The sample is placed under the microscope, and the area of interest is identified using the digital camera and software interface.
4. Laser Cutting: The laser is activated to cut around the selected area. The laser beam is precisely controlled to avoid damage to adjacent tissue.
5. Collection: The dissected tissue is collected, often using a cap or adhesive film, and transferred to a collection tube for further analysis.

Applications

Laser Assisted Microdissection is used in various fields of research and diagnostics:

• Cancer Research: To isolate tumor cells from surrounding stroma or normal tissue for genetic and proteomic analysis.
• Neuroscience: To study specific neuronal populations or brain regions.
• Pathology: For the diagnosis and study of diseases by analyzing specific cell types or structures.
• Forensic Science: To obtain DNA from specific cells in mixed samples.

Advantages

• Precision: Allows for the isolation of specific cells or regions with minimal contamination from surrounding tissue.
• Versatility: Can be used on a variety of sample types, including formalin-fixed paraffin-embedded (FFPE) tissues and frozen sections.
• Non-contact: The laser does not physically touch the sample, reducing the risk of contamination.

Limitations

• Cost: The equipment and maintenance of a Laser Assisted Microdissection system can be expensive.
• Technical Skill: Requires trained personnel to operate the system and interpret results.
• Sample Preparation: Requires careful preparation and handling of samples to ensure successful dissection.

See Also

• Microsurgery
• Molecular Biology
• Pathology
• Genomics

External Links

• [Link to relevant external resources]