Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
56 Cards in this Set
- Front
- Back
|
In electron microscopy which fixatives are used?
|
Glutaralaldehyde for proteins
Osmium tetroxide for lipids (heavy metal thus better deflection of e) |
|
|
In light microscopy what is the usual width of sections?
|
5-8um
|
|
|
What is the optimum resolution of light microscopes?
|
0.2um
|
|
|
For paraffin embedded sections what is the usual optimum resolution?
|
0.6um
|
|
|
How would you achieve better resolution of your section?
|
Use resin embedded sections which allow 0.5->2um width of preparation. = better resolution. Stain with toluidine blue.
|
|
|
Stain for LIPIDS.
|
SUDAN III
|
|
|
Fe (3+)
|
Berlin blue
|
|
|
Glycogen
|
Bests carmine
|
|
|
mucopolysaccharides
|
Colloid Iron
|
|
|
DNA
|
Feulgens Nuclear Reaction
|
|
|
What is Lectin Histochemistry?
|
Used to detect glycoproteins- Lectin is derived from plants.
|
|
|
Give two examples of a lectin stain.
|
Griffonia simplicifolia
Ulex eropeaus |
|
|
What does Griffonia Simplicifolia identify?
|
Microglia cells
|
|
|
What does Ulex europeaus identify?
|
Capillaries.
|
|
|
What is the principle of Immuno Histochemistry?
|
Using marked antibodies to bind to an antigen in the body.
|
|
|
What is the Direct menthod of IHC?
|
Two molecules of marker are bound to a specific AB which binds to the epitrope of the antigen allowing us to identify it.
|
|
|
What is the indirect method of IHC? (Two step)
|
Two secondary AB's bind with the primary antibody which is bound to the antigen = 4x more marker.
|
|
|
What is the AVIDIN-BIOTIN method?
|
Avidin with marker (perioxidase/fluorescence)-
-Bound to Biotin- -Bound to SECONDARY AB - Primary AB- Antigen = 8x more marker per 2nd AB. |
|
|
The advantage of the Avidin- Biotin method?
|
Low concentration = high marker = cheap.
|
|
|
What is Fluorescence microscopy?
|
High energy waves:
UV or B/G Flurochromes (chlorophyl, lipofuscin,tetracyclin) emit visible light. |
|
|
What is Secondary fluroscence?
|
We stain with a flurochrome and observe the emitted wavelengths.
|
|
|
Give 3 examples of Flurochromes?
|
Rhodamine 123 (mitochondria)
Acridine orange Propridium iodide |
|
|
What is FISH?
|
Fluorescence in situ hybridisation
|
|
|
What is in situ hybridisation?
|
When you use a radioactive or marked probe to bind to a DNA or mRNA secquence.
|
|
|
What thickness are EM sections?
|
40->80nm
|
|
|
What is scanning EM?
|
Electons are reflected from the specimen and a picture is formed.
|
|
|
What is autoradiography?
|
One can visulalise radionuclides in tissues. - nucleus, membranes, secretory granules.
|
|
|
Name BASOPHILIC structures
|
Chromatin, ergatoplasm, ground substance of cartilage
|
|
|
Name 3 cytological techniques
|
heamotological smears, sedimentation of body fluids (ascites / csf), abrasions of inner surfaces of the body.
|
|
|
Name ACIDIOPHILC structures
|
Cytoplasm, collagen, mucus, fibrin, elastic fibers..
|
|
|
Histological techniques
|
1- Extripation
2- Probationary excision 3- Probationary puncture 4- Curettage (endometrial scrape) |
|
|
Name the most commen fixation preparation:
|
10% formalin, 40% formaldehyde, the rest distilled water.
|
|
|
Normal tissue section size?
|
1 x 1 x 0.5cm
|
|
|
Advantages of FROZEN sections:
|
Enzyme and Immuno HC can be performed.
|
|
|
Advantages of PARAFFIN EMBEDDED sections:
|
Thin sections/ many staining methods available/ survive for decades.
|
|
|
How are Ground Sections processed?
|
1- Fresh plate is cut from bone
2- Plate ground with abrasive surfaces to polish it. 3- Mounted in CANDADA BALSAM |
|
|
How does decalcification take place?
|
1- Dissolve minerals in HCL/ EDTA
2- Wast in 5% NATRIUM SULPHATE 3- Embed in CELLOIDIN/PARAFFIN. |
|
|
What is the preparation before staining?
|
1- Deparaffinised via xylene/benzene.
2- Rehydrated in ethanol 3- Distilled water used. |
|
|
Acidic or Basic stain?
Haemotoxylin Result? |
BASIC
Nuclei = Dark |
|
|
Eosin
Result? |
ACIDIC
PINK cytoplasm, collagen, mucus, elastic fibers: eosinophilic leukocyte granules. |
|
|
Van Giesons stain
Result? |
ACIDIC
Collagen = RED Muscle = YELLOW |
|
|
Nuclear Red
Result? |
BASIC
NUCLEI = RED |
|
|
Collagen stains x2
|
Blue Trichrome
Green Trichrome |
|
|
Elastin stain?
|
Weigart- Resorcin- Fuchsin
= PURPLE/BLACK. |
|
|
Reticular fiber stain?
|
Silver Nitrate impregnation:
BLACK |
|
|
Neutral Lipid stain?
|
Sudan 3
|
|
|
What is the PAS method?
|
Periodic Acid & Schiffs reagent
|
|
|
What does PAS identify?
|
Neutral: MPS/ Mucoproteins/ glycogen
PURPLE RED. |
|
|
What does Colloid Iron stain?
|
Acidic mucopolysaccharides
|
|
|
What stains mucus (mucin)?
|
Mayers mucincarmine
PINK! |
|
|
How would you stain an Axon?
|
Silver nitrate impregnation = black
|
|
|
How would you stain the myelin sheath?
|
Luxol-Blue produces a blue/green colour...
|
|
|
How would you view astrocytes?
|
Impregnation with AURIC CHLORIDE
Dark Purple |
|
|
What does the PEARL'S reaction stain?
|
It stains haemosiderin (cell storage of iron)
the potassium ferrocyanide turns BLUE. |
|
|
What is the Argentaffin reaction?
|
It turns the pigment melanin BLACK.
|
|
|
What methods would you use to cover a section?
|
Dehydration in ethanol/xylene for clearing...
Canada balsam / DPX medium to fix the glass slide & hey presto! |
