fixation times for certain tissues

Question 1

large tissue

Answer 1

need to opened or perfused to allow fixation penetration

- perfusion involves using vascular system of tissue to distribute fixative

Question 2

eyes

Answer 2

perfuse and fix 48hrs before cutting

Question 3

brain

Answer 3

until firm enough to direct

often 2 weeks

Question 4

renal biopsy

Answer 4

percutaneous needle with ultrasound used to collect

immunofluorescence - frozen

paraffin section - NBF

EM - gluteraldehyde in fridge

Question 5

gastrointestinal

Answer 5

collected through fiberoptic scope 2-3 mm submitted in NBF

large is opened washed and pinned

all layers must be visible

Question 6

liver biopsy

Answer 6

wedge or core needle

for tumor - NBF & embedded

liver panel - group of special stains is preformed to asses liver disease

Question 7

lymph nodes

Answer 7

if lymphoma expected, fresh specimens should be sent

acetic acid and formalin may ,make lymph nodes more prominent and aid in assessing grade of cancer

portion frozen -70
touch preps fixed in alcohol and stained 
portion for EM 
flow cytometry 
remainder for NBF

Question 8

muscle biopsie

Answer 8

fresh in saline dampened on gauze on ice
freeze in cryostat, frozen sections save unstained and tissue aliquot in ultrafreeze

perform enzymatic stains

Question 9

testis

Answer 9

bruin may be used for particularly clear nuclear detail