SECTIONS AND PROCEDURES Flashcards
o recommended when lipids and nervous tissue elements
are to be demonstrated.
o usually done on muscle and nerve biopsies as well as on surgically removed tumors
A. cryostat sections
B. Cold Knife Procedure
C. FROZEN SECTION
D.FREEZING PREVIOUSLY FIXED TISSUE
C. FROZEN SECTION
FROZEN SECTION
Fresh tissue is frozen on a microtome with C02, or on a cryostat, a cold chamber kept at an atmospheric temperature of WHAT ° C?
A. -10° to -20
B. -18° to -20
A. -10° to -20
o ADVANTAGE: rapid processing time with less equipment
requirement, and less need for ventilation in the
laboratory.
o DISADVANTAGE is the relatively poor quality of the final
slide
A. cryostat sections
B. Cold Knife Procedure
C. FROZEN SECTION
D.FREEZING PREVIOUSLY FIXED TISSUE
C. FROZEN SECTION
** give much faster results than paraffin sections**
A. Liquid nitrogen
B. Isopentane cooled by liquid nitrogen
C. cryostat sections
D. Carbon dioxide gas
C. cryostat sections
most rapid of the commonly available freezing agents
A. Liquid nitrogen
B. Isopentane cooled by liquid nitrogen
C. cryostat sections
D. Carbon dioxide gas
A. Liquid nitrogen
it causes a vapor phase to form around the tissue, acting as an insulator that causes uneven cooling of tissue, particularly of muscle biopsies, and making diagnostic interpretation difficult.
A. Liquid nitrogen
B. Isopentane cooled by liquid nitrogen
C. cryostat sections
D. Carbon dioxide gas
B. Isopentane cooled by liquid nitrogen
✓ main disadvantage is that soft tissue is liable to crack
due to the rapid expansion of the ice within the tissue,
producing ice crystals or freeze artifacts.
o It also overcools urgent biopsy blocks, causing damage to
both block and blade if sectioning is done at -70°C or below
A. Liquid nitrogen
B. Isopentane cooled by liquid nitrogen
C. cryostat sections
D. Carbon dioxide gas
e. frozen section
A. Liquid nitrogen
Fix USING: freezing the tissue in Isopentane, OCT, or
Freon 2.2 that has a high thermal conductivity.
A. Liquid nitrogen
B. Isopentane cooled by liquid nitrogen
C. cryostat sections
D. Carbon dioxide
B. Isopentane cooled by liquid nitrogen
adequate for freezing small pieces of tissue
except muscle
A. Liquid nitrogen
B. Isopentane cooled by liquid nitrogen
C. cryostat sections
D. aerosol sprays
D. aerosol sprays
o the morphological detail and resolution of frozen sections
are usually inferior compared to the quality of tissue that has been embedded in paraffin.
A. Liquid nitrogen
B. Isopentane cooled by liquid nitrogen
C. cryostat sections
D. Carbon dioxide
C. cryostat sections
**o Tissue blocks can be frozen by adapting a conventional
freezing microtome gas supply of carbon dioxide gas from a C02 cylinder, or by using a specially made piece of equipment known as cryostat.
**o A piece of filter paper soaked in gum syrup
**
a. cold knife
b. cyostat procedure
c. mountin of tissue block
d. freezing previosly fized tissue
e. Examination of nerve and muscle
f. Freeze-Drying
g. Freeze-Substitution:
a. cold knife
**optimum working temperature of cryostat is **
A. -10° to -20
B. -18° to -20
B. -18° to -20
** brain, lymph nodes, liver, spleen, uterine
curetting, soft cellular tumors**
A. 35°C
C. -5 to -15°C
B. -15 to -25°C f
C. -5 to -10°C
C. -5 to -15°C
non-fatty breast tissue, ovary, prostate, tongue, and GI tract
“POT GN”
A. 35°C
C. -5 to -15°C
B. -15 to -25°C f
C. -5 to -10°C
B. -15 to -25°C f
for fatty breast and omental tissue
A. 35°C
C. -5 to -15°C
B. -15 to -25°C f
C. -5 to -10°C
A. 35°C
**tissue block should be - mm. IN MOUNTING OF TISSUE BLOCK **
A.2-4 MM
B. 3-4 MM
C. 3-25 MM
A.2-4 MM
Sections of formalin-fixed tissue, however, may not adhere to the slide, and will fall off or be detached during staining; TO RESOLVE
A. coated with albumin or chrome-glycerin jelly
B.coated with alcohol or chrome-glycerin jelly
c. albeit cumbersome
d. apes
A. coated with albumin or chrome-glycerin jel
c. albeit cumbersome
**Examination of nerve and muscle fixed with **
a. fixed with 10% buffered formalin + H & E
b.fixed with 15 % buffered formalin+ methylene blue
a. fixed with 10% buffered formalin + H & E
biopsy portion for electron microscopy
a.fixed with 10% buffered formalin + H & E
b. fixed in a buffered solution of glutaraldehyde
c. osmium tetroxide
b. fixed in a buffered solution of glutaraldehyde
POST FIXED FOR NERVE AND MUSCLE
A. osmium tetroxide
B. . fixed in a buffered solution of glutaraldehyde
A. osmium tetroxide
FREEZE- DYING
rapid freezing (quenching) of fresh tissue at
A. 190°C
B. -160°C
B. -160°C
transferring the still frozen tissue block into a vacuum chamber at a higher temperature, e.g. -40°C (sublimation)
A. FREEZE- DRYING
B. MOUNTING
C. FROZEN
D. CRYOSTAT
A. FREEZE- DRYING
A tissue around 2 mm- plunged into isopentane or
propane-isopentane mixture*
A. FREEZE- DRYING
B. MOUNTING
C. FROZEN
D. CRYOSTAT
A. FREEZE- DRYING
a process of dehydration, performed at temperatures low enough to avoid the formation of ice crystals and to circumvent the damaging effects observed after ambienttemperature dehydration
A. FREEZE- DRYING
B. MOUNTING
C.Freeze-Substitution
D. CRYOSTAT
C.Freeze-Substitution
