Contrast

Definition

Contrast is the difference in light intensity between the image and the adjacent background, making details visible under a microscope. It is crucial for distinguishing structures in microscopic samples.

5 Must Know Facts For Your Next Test

1. Higher contrast improves the visibility of fine details in a sample.
2. Staining techniques are often used to increase contrast in biological specimens.
3. Phase-contrast microscopy enhances contrast without staining by utilizing differences in refractive index.
4. Dark-field microscopy increases contrast by illuminating the specimen with light that does not directly enter the objective lens.
5. Fluorescence microscopy uses fluorescent dyes to create high-contrast images based on emitted light.

Review Questions

• Why is contrast important when viewing specimens under a microscope?
• What are two common methods used to enhance contrast in microscopic samples?
• How does phase-contrast microscopy differ from traditional bright-field microscopy?

Related terms

Resolution: The ability of a microscope to distinguish two close objects as separate.

Staining: The process of adding dyes to specimens to increase contrast and visibility.

Bright-field Microscopy: A standard microscopy technique where light passes through the sample to create an image.