What is the resolution capability of phase contrast microscopy (PCM)?

Phase contrast microscopy (PCM) is a powerful technique used to enhance the contrast of transparent and nearly transparent specimens, making it particularly valuable in biological and medical fields. The resolution capability of PCM is approximately 0.25 micrometers, which allows it to visualize cellular structures at a high level of detail.

This resolution is achieved because PCM exploits differences in the refractive index of cellular components, converting phase shifts into differences in brightness. The inherent capabilities of light microscopy, including the wavelength of light used and the optical components of the microscope, also play a role in determining the maximum resolution. In the case of PCM, the high resolution of about 0.25 micrometers enables the observation of fine cellular features such as organelles and subcellular structures, facilitating a better understanding of cellular morphology and function.

Other options represent resolutions that are either too coarse to accurately detail the capabilities of PCM or are characteristic of different microscopy techniques. For instance, 0.5 micrometers is too imprecise for PCM, while resolutions of 1 micrometer or 0.1 micrometers exceed or fall short of the typical range for this microscopy method.