Differential interference contrast (DIC) microscopy, also known as Nomarski microscopy, is a type of microscopy that is commonly used to observe living cells. In this article, we will discuss how to use a DIC microscope to observe living cells.
Principle of DIC Microscopy
The principle of DIC microscopy is based on the interference of polarized light beams that are split by a polarizing prism. The split beams are then passed through a series of optics, including a Nomarski prism, which converts the light waves into two separate polarized beams that are slightly out of phase with each other. When the beams recombine, interference patterns are generated, which produce a 3D-like image of the sample.
In DIC microscopy, the contrast of the sample is enhanced by the differential interference of the polarized light beams, which makes it possible to observe living cells with high resolution and contrast.
Sample Preparation
Sample preparation for DIC microscopy is relatively simple. Living cells are typically cultured on a glass coverslip or in a specialized chamber that is designed for microscopy. The cells are then washed and placed in a buffer solution to maintain their physiological conditions during imaging.
Image Acquisition
To observe living cells using DIC microscopy, the microscope is set up with the appropriate optics, including a polarizing prism, a Nomarski prism, and a high numerical aperture objective lens. The sample is then focused using the fine focus knob, and the contrast and brightness of the image are adjusted using the DIC control knobs.
Image Processing
Image processing is typically not required for DIC microscopy, as the technique produces high contrast, 3D-like images of living cells without the need for staining or other modifications. However, the images can be adjusted for brightness and contrast, and annotations can be added using image processing software.
Applications
DIC microscopy is used in a variety of fields, including cell biology, microbiology, and neuroscience. In cell biology, it is used to study the structure and function of living cells, including cell division, movement, and differentiation. In microbiology, it is used to observe bacteria and other microorganisms, including their interactions with host cells. In neuroscience, it is used to observe the structure and function of living neurons, including their interactions with other cells and the environment.
Conclusion
DIC microscopy is a powerful technique that enhances the contrast of living cells, making it possible to observe their structure and function with high resolution and contrast. Sample preparation is relatively simple, and image acquisition produces high contrast, 3D-like images of living cells without the need for staining or other modifications. DIC microscopy has many applications in cell biology, microbiology, and neuroscience, making it an important tool for scientific research and discovery.
