Phase contrast - You always got a sample with you

Phase contrast is a widespread method in transmitted light microscopy. Especially in biology and medicine with their native samples this contrast method often is the easiest way to examine thin, unstained sections, smears and emulsions with almost no absorption.

The necessary hardware for Phase contrast 

• Figure 1: Objective with evaporated phase ring
• Figure 2: Illumination slot
• Figure 3: Centering telescope
• Figure 4: Phase ring

An objective with an evaporated Phase ring is combined with a respective illumination slot, placed in the focal plane of the condenser. The Centering telescope is a helpful tool to bring the round illumination ring to a perfect overlap with the partly transparent Phase ring. 

How to use the Phase Contrast accessories

Testing your microscope hardware

The more interesting is how to get a suitable sample to check the performance of the microscope hardware.

Good news: You always have the perfect sample at hand. To be more precise, it’s the mucous membrane of your oral cavity. Just scrape off a sample with your forefinger, place it on your objective slide with a coverslip on top and start the investigation. 

Josefine Neuendorf © 2014 - Squamoous epithelia cells - Comparison between Brightfield and Phase Contrast

Only in Phase contrast squamous epithelia cells with their nuclei, mucous filaments and even bacteria can be detected with a 400X total magnification, while in Brightfield only hazy outlines are visible. No need to purchase the famous rabbit testicle sample for checking your Phase contrast.

                                 Section of rabbit testicles - Comparison between Brightfield and Phase Contrast

Take the chance and check your Phase contrast microscope, find out the difference between positive and negative Phase contrast version.