BLG 311 Lecture Notes - Lecture 2: Phase-Contrast Microscopy, Optical Microscope, Electron Microscope
Document Summary
Optical microscopy: cell biology began with the light microscope. One advantage of optical microscopy is that it is undestructive. Schleiden and schwann propose that all plant and animal tissues were aggregates of individual cells. Their proposal in 1838, known as the cell doctrine, marks the formal birth of cell biology. Light microscopy can resolve details 0. 2 m apart. When light passes through a living cell the phase of light is changed based on the cells refractive index. Magnification: increase int eh size of an object, no limit to magnification. Resolution: separation of the individual components of an object which previously appeared as one. Resolution limit: reached when additional magnification does not separate further detail the result is simply an enlarged blurry image. Detection: able to visualize light signals from objects much smaller than 0. 2 mm. Magnification the magnification of structures by use of the microscope calculated by eyepiece magnification multiplies with objective magnification.
