ljussmikroskopi

Ljussmikroskopi (light microscopy) is a technique using visible light and lenses to magnify small specimens, permitting observation of structures too small for the unaided eye. The basic principle involves transilluminating or reflecting light through the specimen; lenses form a virtual image that can be viewed by the observer or recorded by a camera. The resolution limit, defined by diffraction, is approximately 200 nanometres, which restricts observation to structures larger than this threshold but allows visualization of cells, tissues and microorganisms.

Historical development of ljussmikroskopi began in the early 17th century with the invention of the microscope by Dutch opticians Huygens, van Leeuwenhoek, and Hooke. Over the following centuries refinements such as higher quality glass and improved illumination (e.g., Köhler illumination) expanded the method’s usefulness. The introduction of phase‑contrast, differential interference contrast and fluorescence variants in the 20th century further extended the range of detectable structural and functional details.

Modern ljussmikroskopi systems are employed across biology, medicine, materials science and environmental studies. In cell biology they enable detection of subcellular organelles and cytoskeletal elements, while in pathology they aid in diagnosis of tissue biopsies. In materials science, light microscopes are used to inspect thin films, composite interfaces and surface textures. The technique’s advantages include relative low cost, ease of use, rapid specimen preparation, and the ability to view live specimens. Limitations arise primarily from limited resolution compared to electron microscopes, light scattering in thick specimens, and the need for staining or labeling to enhance contrast.