Introduction

Question 1

Hematoxylin

Answer 1

Basic dye that stains (purple):
1) DNA - heterochromatin and nucleoli
2) Cytoplasmic RNA/ribosomes
3) extracellular complex carbohydrates (ex; cartilage)

Question 2

Fixation

Answer 2

• Typically Formaldehyde
• Embedding a paraffin and thinly sliced on a microtome
• Hematoxylin & Eosin (H&E) staining: most common for histological preps

Question 3

Basophilia

Answer 3

ability of anionic groups to react with a basic dye

Question 4

Eosin

Answer 4

Acidic dye that stains (pink):
1) general membranous cytoplasmic organelles
2) intracellular fibers (ex; muscle cells)
3) extra cellular fibers (ex; connective tissue)

Question 5

Acidophilia

Answer 5

Ability of cationic groups groups to react with acidic dye

Question 6

Electron microscopy

Answer 6

higher magnification than light microscopy

Question 7

Scanning electron microscopy (SEM)

Answer 7

surface

Question 8

Transmission electron microscopy

Answer 8

inside

Question 9

immunoflourescence

Answer 9

• visualization of proteins in fixed tissues
• direct: antibodies directly label with fluorescent marker
• indirect: primary and secondary antibodies

Question 10

Direct immunofluorescence

Answer 10

antigen to antibody

Question 11

Indirect immunofluorescence

Answer 11

antigen to primary antibody to fluorescent secondary antibody
more cost efficient

Question 12

polycolonal and monoclonal antibody production

Answer 12

1) Inject antigen into the animal
2) bleed them out
3) collect antibodies

Question 13

monoclonal antibody production

Answer 13

1) isolate B cell (antibody-making WBC) on cell culture
2) find one cell that makes desired antibody
3) fuse to a myeloma, keep growing

Question 14

Immunogold labeling

Answer 14

Antibody conjugated to a gold particle (electron-dense secondary antibody due to gold)
Used under TEM to find proteins proteins (ex; proteins found in secretory vesicles)

Question 15

In situ hybridization

Answer 15

• visualizing mRNA in tissues or living organisms
• DNA or RNA probe conjugated to fluorescent probes, biotin or digoxigenin
• Uses DNA/RNA probe instead of antibody
  ex) fruit fly embryos and fluorescence in trisomy 21
  Regular In situ hybridization shows up purple and fluorescent shows up fluorescent

Question 16

Hematoxylin and eosin staining steps:

Answer 16

1) Hematoxylin (water soluble)
2) series of alcohol treatments to dehydrate the sample
3) eosin (alcohol soluble)
4) cleared with decreasing concentration of alcohol (xylol/toluol)
5) permanently embedded in a non-aqueous medium, cover-slip, and sealed

Question 17

Cell Structure

Answer 17

Cell function is defined by shape, cytoplasmic organelle composition, cytoplasmic protein composition, and surface marker identity

Question 18

visualizing microvilli

Answer 18

H&E staining, appearing hazy outside cells
function: increase SA
Found in: placenta, small intestines
Small Intestines: associated with a glycocalyx - mixture of carbohydrates and glycoproteins
Intestines: terminal digestive enzymes (for proteins and carbs)

Question 19

Visualizing membrane protein

Answer 19

Existence of plasma proteins confirmed by freeze-fracture
Causes membrane to split:
- E-face: backed by extracellular space
- P-face: backed by cytoplasm

Question 20

Membrane trafficking

Answer 20

1) endocytosis
- pinocytosis
- phagocytosis
- receptor-mediated endocytosis
2) exocytosis

Question 21

Pinocytosis

Answer 21

a form of endocytosis, every cell does this as a part of natural homeostasis (equilibrium-healthy)
Visualized by light and TEM - large vesicles under light and small under EM

Question 22

Phagocytosis

Answer 22

Specific endocytosis to neutrophils
- need pseudopodia to engulf
visualized by EM

Question 23

Exocytosis - secretory cells

Answer 23

ex) endocrine/exocrine cells, neurons
Signal results in flux of Ca2+ and vesicle release

Question 24

Protein making organelles

Answer 24

Rough ER and golgi apparatus

Question 25

Rough Endoplasmic reticulum

Answer 25

High level of protein synthesis (stains with basic dyes-basophilic)
- ergastoplasm
- interconnected flattened sheets (cisternae), sacs and tubes of membrane
- attached ribosomes

Question 26

Smooth endoplasmic reticulum

Answer 26

flattened sheet without ribosomes
function: lipid and steroid metabolism + calcium storage

Question 27

Golgi apparatus

Answer 27

Visualized through EM
- stacks of flattened membrane sheets - sit next to nucleus
- negative staining (doesn’t stain)
function: protein maturation, modification, and storage

Question 28

Ergastoplasm

Answer 28

portion of cytoplasm that stains with basic dyes, extensive rER

Question 29

Mitochondria

Answer 29

LM: seen as dark small dot
EM: visualized the various membrane systems (cristae + outer and inner membranes)
- abundant in metabolically active cells
Inner membrane has elementary particles
- tennis racket-shaped structures
- enzymes of respiratory chain
- project into the matrix

Question 30

Peroxisomes

Answer 30

containing detoxifying enzymes, abundant in the liver
increase in # depending on diet and alcohol intake
EM) membrane-bound containing electron-dense crystalloid (staining dark)

Question 31

Lysosomes

Answer 31

Internal cell digestion of phagocytosed material or dying organelles
- membrane-bound, only visible with histochemical stains

Question 32

Cytoplasmic components

Answer 32

Cytoskeleton:
microtubules, actin filaments, and intermediate filaments
Cytoplasmic inclusions:
glycogen granules, lipid droplets, and crystalline inclusions

Question 33

Visualizing the cytoskeleton

Answer 33

Each component can be visualized using immunofluorescence
- microtubules: alpha-tubulin (also visualized under TEM)
- Actin: alpha-actin
- intermediate filaments: alpha-vimentin

Question 34

Microtubules

Answer 34

Intracellular vesicular transport
Movement of cilia and flagella
Mitosis: attachment of chromosomes to mitotic spindle
Cell elongation and migration
Cell shape and polarity

Question 35

Actin filaments

Answer 35

Constitute a large portion of the cytoplasm (even nonmuscle)
- only visible under immuno-fluorescent techniques
Function:
- anchorage and movement of membrane proteins
- core of microvilli
- locomotion of cells and movement
- extension of cell processes - filopodia

Question 36

Intermediate filaments

Answer 36

Not as dynamic thus thought to be mainly structural
Heterogenous
- keratins: found in epithelial cells (skin: hair+nails)
- Vimentin: most abundant
- Neurofilaments: axons of nerves
- Laminins: found in nucleoplasm

Question 37

ID cells with glycogen granules

Answer 37

Liver, skeletal muscle, ooctye, and endometrium during the secretory phase all have lots for energy needs

Question 38

Crystalline inclusions

Answer 38

Crystals of Reinke, found throughout the body and can be associated with tumors
function: unknown

Question 39

Lipid droplets

Answer 39

Adipocytes - fill cytoplasm (for energy)
Absorptive cells - intestines (absorption)
Goblet cells - mucous/lipids (lubrication/neutralization of acid)
Steroid hormones - cholesterol

Question 40

Nucleus

Answer 40

TEM
Heterochromatin: dark staining
Euchromatin: light staining

Question 41

DAPI staining

Answer 41

A fluorescent stain (blue) that binds strongly

Question 42

Nuclear pores

Answer 42

Function:
regulated mRNA export and protein import

Question 43

Cell division and death

Answer 43

Cell death disorders: AIDs, Alzheimer’s disease, Parkinson’s disease, aplastic anemia, myocardial infarction
Cell division disorders: cancer, lupus, viral infections

Question 44

Cell death

Answer 44

Necrosis and apoptosis

Question 45

Myocardial infarction (heart attack)

Answer 45

cell death by necrosis
neutrophils lead to inflammation