L1. introduction+Staining+Cell Flashcards
What is the diameter of the aorta
5cm
What is the cross sectional diameter of a small artery
1mm
What is an organ?
group of tissues that are assembled into units that serve a broader function
What is the diameter of a RBC?
7-8 um
What is the diameter of a typical cell?
10um
What is the diameter of a nuclei?
3um
What is the resolution for LM?
up to 0.25um are visible by LM
What is the resolution for EM?
anything less than 0.25um is visible through EM
What is the size of a mitochondria?
0.2um to 3um
What is the diameter for individual cytoskeletal filaments?
5nm -10nm
what is the diameter of microtubules?
25nm
What is the diameter of a DNA helix?
2nm
What is the process for histology?
- fixation
- dehydration
- embedding
- sectioning
What is the difference between the process for LM and EM?
LM: embedding in parrafin
sectioning is thick with 5-10um
EM: embedding in plastic/resin
sectioning is thin with 25-100nm
What is the process of fixation?
cross-link proteins and macromolecules with aldehydes
maintains tissue architecture for microscopic sectioning
What are the different staining types?
- histochemical : based on charge low specificity
- immunochemical: based on antibodies binding to antigens; high specificity
- fluorescent tags: linked to various antibodies, facilitates optical sectioning
What pH is eosin and hematoxylin?
eosin: pink (acidic)
hemotoxylin: blue ( basic)
What does Osmium Tetroxide stain for? which kind of microscopy is it used in?
Binds with lipids.
Used in EM
What microscopy can optically section an image
confocal microscopy : can take 3D images
