Question

Which of the following statements is correct regarding Phase Contrast microscopy?

• A. Used for the study of living cells
• B. Based on the scattering of light and used a dark field condenser
• C. Related to retardation and to the thickness of the object
• D. The best method of studying nonliving ultrastructures

Answer 1

The correct option is A Used for the study of living cells

Phase Contrast Microscope was developed by Zernike. He received 1953 noble prize for this work. The microscope has a phase plate and an annular diaphragm. They bring about changes in light rays passing through the specimen producing differences in light intensity. Denser parts alter path of light more than the thinner parts. This produces varying contrast for different regions. Hence staining is not required and the difference between denser and lighter parts of the specimen is revealed by the phase difference.
The microscope is useful in the study of small living organisms, living cells, constituents of living cells, effect of various factors over living structures, and study of various cellular events like behaviour of chromosomes during mitosis and meiosis, spindle formation, cytokinesis, pinocytosis, phagocytosis, cyclosis, glandular secretions, spermatogenesis, oogenesis etc.