What is meant by dark field microscopy?

Listen to pronunciation. (… MY-kroh-SKOPE) A microscope (device used to magnify small objects) in which objects are lit at a very low angle from the side so that the background appears dark and the objects show up against this dark background.

What is dark field microscopy and how does it work?

How Does Darkfield Microscopy Work? Darkfield illumination requires blocking most of the light that ordinarily passes through and around the specimen, allowing only oblique rays to interact with the specimen. This allows these faint rays to enter the objective. The result is a bright specimen on a black background.

What is the difference between bright field and dark field microscopy?

Specimens which are transparent are often stained and observed under a bright field microscope. Specimens which absorb little or no light are kept unstained and observed under a dark field microscope.

Where is dark field microscopy used?

Darkfield is used to study marine organisms such as algae, plankton, diatoms, insects, fibers, hairs, yeast and protozoa as well as some minerals and crystals, thin polymers and some ceramics. Darkfield is used to study mounted cells and tissues.

Is staining required for dark field microscopy?

Since staining can kill specimens, there are times when darkfield microscopy is used instead. In darkfield microscopy the condenser is designed to form a hollow cone of light (see illustration below), as opposed to brightfield microscopy that illuminates the sample with a full cone of light.

What microscopy method is used for detecting syphilis?

“A diagnosis of syphilis is confirmed by using dark field microscopy to demonstrate T. pallidum in material from suspected lesions, or regional lymph nodes (Creighton, 1990). A positive dark field result is an almost certain diagnosis of primary, secondary, or early congenital syphilis.

What type of specimen is best suited for dark field microscopy?

The best specimens for dark field are those that have refractive objects scattered about with empty space between them. No dark field occurs if objects are too crowded or if a thick solid specimen turns light into the microscope.

Can chlamydia be seen under a microscope?

The discharge is usually clear and stringy. In a sexual health clinic, the doctor or nurse may take a specimen and look at this under the microscope. They are looking for signs of infection such as an increased amount of white blood cells, and the chlamydia bacteria.

Which human disease can be diagnosed using dark field microscopy?