History of Cell Bio and Microscopy

Question 1

Process of sectioning:

Answer 1

1. Fix tissue
2. Remove water from cells
3. embed them in a rigid agent (parrafin for LM, plastic for EM) for cutting into thin
4. remove embedding and add water back in
5. mounting agent
6. look at sample

Question 2

condenser focuses light on _____

objective and eyepiece focus light on ____

Answer 2

specimen

eye

Question 3

Type of microscopy that:

• displays differences in light intensity.
• details down to 0.2micrometers
• best if used w stains
• bad resolution
• cant see much of live specimens

Answer 3

bright field microscopy

Question 4

Type of microscopy that:

• displays differences in phase of light bouncing around specimen as differences in contrast (visible to eye)
• higher contrast (can get better resolution w/o staining
• live samples
• need thin specimen

Answer 4

phase or interference contrast microscopy

Question 5

• picks up indirect light scattered off structures rather than direct light passing through
• seeing borders and surfaces of samples; seeing tiny structures
• can be used for live samples
• lwo light level can make it hard to see things, but more incident light could be bad for sample

Answer 5

dark field microscopy

Question 6

type of microscopy that:

• marks specific structures using immunocytochemistry: with an immobilized sample:

1. primary Ab to Ag of interest
2. 2ndary antibody attached to fluorophore against primary Ab
3. excite fluorophore, “see” Ag

• identifying location of specific structures, tracking structures before and after an intervention
• expensive, have to know what you’re looking for and make Abs, have to excite with specific wavelength with fluorophore
• can see many diff proteins by fluorescing at different wavelengths

Answer 6

fluorescence microscopy

Question 7

• upside-down light microscope
• increase speed of electrons decreases wavelength (??)
• magnetic lenses focus beam of electrons on fluoresent screen
• resolution up to 0.001 micrometers (1 nm)
• can see cellular details
• super expensive, only works for certain structures
• putting oil between lens and slip gives higher resolution

Answer 7

electron microscopy

Question 8

• works by interference of light waves as a result of distortion by cellular component. Light forms series of diffraction lines and our eye interprets this additive and subtractive interference

Answer 8

light microscopy