Optical microscopy is intensively used in the life sciences and since the invention of the first microscope about 400 ago new optical imaging methods and techniques have been constantly developed. Recently, super-resolution optical techniques allowing to image live samples with nanometer spatial resolution have been reported opening a new field in optical imaging: Nanoscopy. The Nobel Prize in Chemistry 2014 recognized this important achievement.
Advanced optical methods provide tools for observing objects with high spatial resolution, high spectral resolution and high sensitivity. These methods are based on pure optical effects as well as effects that involve photon-matter interaction. Optical manipulation uses light-matter interaction to trap, manipulate micro/nano particles and ablate live samples with high precision. The Nobel Prize in Physics 2018 recognized the invention of optical tweezers and their application to biological systems.
The course will cover an introduction on image formation of unstained samples, following with super-resolution and concluding with optical manipulation techniques. The aim of the course is to provide the basic physics background to these optical microscopy methods, and to understand the importance, capabilities and limitations of these methods. Examples of applications in neurobiology will be studied and discussed from literature.
Syllabus
- 1. Imaging unstained samples
1.1. Optical microscope: image formation brightfield and dark field.
1.2. Magnification, laterals resolution / depth of focus.
1.3. Digital cameras for bio-imaging.
1.4. Phase contrast techniques: Zernike, Differential Interference Contrast.
1.5. Quantitative phase / digital holographic microscopy.
- 2. High => Super-Resolution fluorescence microscopy
2.1. Fluorescence microscopy – short review
2.2. Increasing axial resolution – TIRF, increasing the depth – 2 photon microscopy
2.3. Increasing lateral and axial resolution – confocal vs STED and PALM
2.4. FRET
- 3. Optical manipulation
3.1. Optical tweezers and scalpels – working principles, properties.
3.2. Optical manipulation of bio-samples /living cells.
3.3. Probing forces expressed by cells and biomolecules with optical tweezers.
3.4. Focal stimulation of living cells by optical manipulation: mechanical and biochemical stimulation. Mechanotransduction.