Application of dark-field microscopy for detection of DNA and protein

Abstract

Dark-field microscopy (DFM) can be used to observe living cells and microorganisms. In contrast to a bright-field microscopy, the entire field of view in DFM is dark by default and the dark background provides a high contrast. And when the researchers placed the target samples in the path of the light cone, it appeared bright because it was on an almost black background, so it shows outstanding detail. DFM is a technique to improve the contrast of specimens with poor imaging quality under conventional illumination. After the direct light is blocked by the opaque aperture in the condenser, the light passing through the sample at an inclined angle is reflected into the microscopy objective lens through diffraction, refraction and reflection, producing a bright sample image. The DFM is preferred for opaque, low transparency and low contrast specimens, especially when staining is not a viable option. DFM has the unique advantages of being easy to modify and effective, so this technology shows a diverse of different applications. Herein, this research outlines the characteristics of DFM and analyzes its application in DNA and protein detection.