[BIO 320] - Final Exam Guide - Comprehensive Notes fot the exam (298 pages long!)
Document Summary
A few points on microscopy since it was quickly reviewed in class. In microscopy, magnification refers to the enlargement of the object being studied, while resolving power pertains to the capacity of an optical medium, such as a lens, to distinguish between proximate objects as distinct images . Limit of resolution light wavelength and numerical aperture are determinants of the 200nm limit of resolution: limit of resolution does not mean we cannot see things that are smaller than the limit. Bright-field microscope: light passes through specimen (cell) and forms image directly. Dark-field microscope: light hitting the specimen will scatter and few rays will be able to pass through the objective, creating a bright image against a dark background. Phase-contrast microscope: cell thickness and density effect the phase of light passing through the specimen, thereby amplifying the interference/combination of waves and increasing contrast. Differential-interference-contrast microscope: similar to phase contrast, but better for imaging live cells.
