TECHNIQUE CONTRAST - Optical Microscopy

Dark Field Ultramicroscopy - Illumination

Sideways - no direct light

Dark Field Ultramicroscopy

Signal from small particles is amplified

Bright Field Ultramicroscopy - Illumination

Below

How does bright field microscopy work?

Illuminates from bottom so can see sample

Reflection Microscopy/ Epi-Illumination - illumination

from above

Reflection Illumination - how it works

Against dark surface, particles and light reflect

What materials can reflection illumination work on

Metallics, ceramics

Polarized microscopy - illumination

Bottom

Polarized microscopy

Uses polarizer to look at birefringent materials

Phase contrast microscopy

Turn pure phase object into pure amplitude

What is phase contrast microscopy used for

Biological molecules

Differential interference contrast microscopy - illumination

bottom

Differential interference contrast

Enhances contrast in transparent samples, uses interferometry

What can DIC be used for?

Biological samples

Confocal microscopy

Fluorescence microscopy, gives 3D images

Uses pinhole to scan specimen