Final answer:
The main advantage of a phase contrast microscope over an electron microscope is its ability to observe living cells without killing them, utilizing light to enhance contrast. It's ideal for studying live, unfixed, and unstained specimens.
Step-by-step explanation:
An advantage of using a phase contrast microscope over electron microscopes is that it allows for the observation of living cells. Electron microscopes require specimens to be in a vacuum and use a beam of electrons, which provide higher magnification and resolution but kill the specimen in the process. In contrast, phase contrast microscopy uses light to increase contrast between different parts of the specimen, which is particularly useful for viewing live, unfixed, and unstained specimens because it does not require the specimens to be killed, making it a cost-effective tool for examining biological processes in real-time.
Furthermore, phase contrast microscopy can enhance contrast between structures with different refractive indices without the need for staining, which is beneficial when observing delicate structures within living cells. Such microscopes are invaluable for studying cell movement, cell division, and other dynamic processes that cannot be observed using electron microscopy.