Lecture notes - Cell And Molecular Biology (Microscopy/cytology)

Microscopy and Cytology
Cytology = study of cells

- Cell = basic – functional and unit
- Tissues = all made of cells – extracellular matrix = elaborated by cells
- Most mammalian cells = mircoscopic
- Microscopy = use of microscope

Microscope = optical equipment for viewing samples/cells – magnified

- Visualize cells, organelles, cell cultures

4 types = Light (simple), fluorescence, confocal and Electron

- Light = for unstained cells
- Others need stains

Light microscope = several part

Light = from source – to objective lens

- Light = through condenser – focuses light on sample (gives max. brightness)
- Light goes through sample
- Light through objective lense – magnifies image – passes through eyepiece (X10)
magnification

For unstained living cells – 2 types

- Phase Contrast microscopy (thin layers of cells – not thick tissues)
- Differential Interference contrast (very small/thick details)

Flourescence microscopy:

- For specific cellular molecules
- ‘glow’ against dark background
- Cells = fixed/living
- Flurochromes = dyes (directly/indirecly associated with cellular molecule)
- Multiple flurochromes may be used



Hystology = study of tissue

Several samples used in cytology:

- Fluids
- CSF
- Nipple discharge
- Gastric/urine
- Secretions (cervical/smear)

3 catagories of cytology samples

- Exfoliative