Factors affecting fixation Flashcards
1
Q
Fixative of choice
A
10% Neutral Buffered Formalin
2
Q
Must be performed as soon as possible; ___-___mins after blood supply is cut off
A
20-30 mins
3
Q
Tissue-to-Fixative Ratio
A
1:10 or 1:20 (tissue to fixative ratio)
4
Q
Penetration Rate
A
1mm/hr (but slows down as it goes deeper to the
tissue)
5
Q
Larger → Longer fixation time, more fixative
A
Thickness of Specimen
6
Q
Light Microscopy
A
2cm2 x 0.4cm
7
Q
Electron Microscopy
A
1-2 mm2
8
Q
____ → wash with NSS
____ → cut into slices → fixed
____ → flushed out with saline
A
Mucus
Fat
Blood
9
Q
optimum pH
A
6-8
10
Q
Optimal Temp (routine)
A
Room temp to 45°C
11
Q
Thus, maintain tissues at slightly hypertonic solution (____-___ mOsm)
A
400-450
12
Q
Hastens fixation
A
Agitation
