[Title will be auto-generated]

Microscope Comparison Chart By: Tejas Jha Type Brightfield

Features Specimens appear dark against a light background. Specimens may be living or may be killed and stained. Structures smaller than about 0.2 micro-meters cannot be resolved.

Advantages Inexpensive and easy to use.

Darkfield

Specimen appears light against a dark background. Light from illuminator is blocked from entering objective lens directly.

Only the light that is reflected from the specimen can enter the objective.

Can be used to see specimens that cannot be seen by brightfield microscope or that do not stain well.

Phase contrast

Uses the differences in light from the illuminator and that diffracted from the specimen to create contrast.

Creates contrast in unstained living cells.

Differential interference contrast (DIC)

Prisms are used to split two beams of light. Differences in the refraction of the light is used to create contrast.

Gives a three-dimensional appearance to unstained cells. The refraction of the light by the prisms adds color to the specimen.

Picture

Fluorescence

Special fluorescent stains are used along with filters that allow only certain wavelengths of light to reach the specimen. These wavelengths activate the fluorescence of the stains and cause them to glow.

Stains can be targeted to specific types of microbes that are then illuminated by the fluorescence if they are present in the sample.

Confocal

Uses computers to precisely guide lasers to illuminate the specimen.

Fluorescent stains are used and activated by the lasers.

Very precise areas of the specimen can be examined at one time. Computers can then combine multiple images of the same specimen to create a very detailed image.