MCB-4403 Lecture Notes - Lecture 1: Scanning Electron Microscope, Transmission Electron Microscopy, Gram Staining
21 Jan 2017
School
Department
Course
Professor
Document Summary
The resolution of our eyes is limited, at 150ul=1/7mm=2/200in. The resolution of our eyes depends on the distance between two photoreceptor cells and our retina. Compound microscope: the image is formed by the action of 2 or more lenses. The image from the objective lens is magnified again by the ocular lens. To find the total magnification of the image. Simple microscope has only one lens (cid:1854)(cid:1862)(cid:1855)(cid:1872)(cid:1861)(cid:1874) (cid:1871) (cid:1855)(cid:1873)(cid:1853)(cid:1870) (cid:1871) To increase resolution, you make the number smaller: Wider lens closer to specimen n: refractive index nair=1. Dark objects on the specimen become visible against a bright background. Light that reflects off of the specimen does not enter the objective lens. Bright objects on the specimen become visible against a dark background. Light that reflects off of the specimen enters the objective lens. Light has to enter the objective lens here because it is the bright objects that are of interest in a darkfield.
