Microscopes are used to magnify and views objects in greater detail. There are different types including light and electron microscopes. Light microscopy branches out further into Bright field, Phase contrast, Fluorescence and Dark field.2 Light microscope uses visible light which is refracted as it passes through the object, travels through the objective lens where the image of the object is magnified. The lens are able to magnify at different strengths 10x 40x and 100x. The condenser lens focus the intensity of light onto the specimen producing clarity and illumination.
Microscopy magnify object and create detail of the object which is resolution. A human eye is able to distinguish two separate points from each other as long as they are no closer than 0.2mm together otherwise the two points start to look like one. 1 A light microscope has a resolving power of 0.2µm allowing greater detail of a specimen. 3
Bright field microscopy is best when using dead cells which have been stained or pigmented specimens such as blood smears where the pigmentation will be easily seen. Staining kills the cells so living specimens can’t be used 2 Bright field uses light which has been focused using the condenser to pass through the specimen, the objective and ocular found in the eyepiece are then used to magnify the object. 4 Since the specimen is viewed this way it appears to look dark against a bright background.
Bright field can’t be used to see most specimen since they don’t have enough contrast or natural pigmentation to see the detail of the cell’s structure. To overcome the problem of viewing low contrast specimen which are called Phase objects, Phase Contrast microscopy is used, examples of phase objects are sperm.
Highly refractive structures such as the granule bends light waves at a higher degree then low refractive structures, they also delay the speed of the light by ¼ wavelength, some of the light is lost. These light waves are out of phase with each other...