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Introduction to contrast techniques
Many biological samples are nearly transparent under standard brightfield illumination, making it difficult to distinguish cells and structures of interest. Contrast-enhancing microscopy techniques improve the visibility of unstained specimens by converting differences in refractive index or light scattering into intensity differences.
The best technique depends on several factors:
- Sample type
- Sample thickness
- Imaging depth
- Resolution requirements
- Available microscope optics
- Experimental workflow
Scientifica has published articles that introduce the four commonly used transmitted-light contrast techniques, explaining how they work and how to set them up:
Which contrast technique should I use?
To begin to work out which technique is best for your experiment, start with the comparison tables below.