chapter 3 Flashcards
what are the units of microscopes in order?
mm –> um –> nm goes over three decimal places to left each
what are uses for compound light microscopes
stained or live specimens and count microbes
what ocular lens do?
to view it is 10x magnification
what does illuminator do?
light source
what is the condenser do?
focuses light
what are the objective lens?
to magnify 4x 10x 40x 100x
what is the total magnification?
objective x ocular
what is the features of phase contrast microscope?
special condenser that improves contrast
between specimen and surrounding medium
what are the uses of phase contrast microscopes?
live, unstained specimens; internal structure
motility, size, and shape
what are the features of darkfield microscopes?
uses darkfield condenser
specimen appears light against black backgroudn
what are the uses of darkfield microscopes
living microbes that are invisible in bightfield
what are the features of fluorescence microscope?
UV light to illuminate fluorescent microbes
what are the uses of fluorescence microscope?
Antibody research to identify microbes
what are the uses of electron microscope?
uses beam of electrons focused by electromagnetic lenses
specimen are pretreated with chemical or dyes
specimen are dead
what are the uses of electron microscope?
detained internal and external structures
viewing viruses
what are the types of electron microscopes?
scanning (SEM)
transmission (TEM)
what doe SEM feature?
detailed 3D images
whole cells are coated with gold, an electron beam passes over cells, electrons are scattered
objects are magnified 1000 t 10000 times
what are the uses for SEM?
detailed external features
viewing viruses
what are the features of TEM?
ultrathin section of specimen are cute
section are treated with lead
beam of electrons passes through section
objects are magnified 10000 to 100000 times
what are the uses of TEM?
detailed internal structures
viewing viruses
