Improved contrast microscopy: modification of bright field for urine sediment visualisation

Area of Science:

• Microscopy
• Optical Physics
• Biomedical Imaging

Background:

• Phase contrast microscopy is standard for urine sediment analysis.
• Bright field microscopy struggles with subtle refractive index differences.

Purpose of the Study:

• To introduce a novel method for enhancing contrast in bright field microscopy.
• To provide an accessible alternative to phase contrast microscopy for urine sediment examination.

Main Methods:

• A disc of specific dimensions was strategically placed within the bright field microscope.
• The disc leverages Fresnel diffraction to alter light wavelengths, creating contrast.
• Constructive and destructive interference enhance perceived differences in specimens.

Main Results:

• The technique effectively visualizes and differentiates urinary elements including epithelial cells, red blood cells (RBCs), and casts.
• Bacteria and crystals are also clearly discernible.
• The enhanced bright field images closely resemble those from phase contrast microscopy.

Conclusions:

• The novel bright field microscopy method significantly improves contrast.
• This technique provides an alternative to phase contrast microscopy for urine sediment analysis.
• The visual quality of images is comparable to phase contrast microscopy.