DNA/RNA stains Flashcards
DNA/ RNA stains (3)
1.feulgen reaction
2.methyl green-pyronin Y
3.may- grunwald giemsa
feulgen reaction preferred fixative
anything but bouins
- don’t use an acidic fixative bc of HCL
control tissue for feulgens
no control tissue, internal control
feulgens principle and purpose
principle; HCL hydrolyses nucleus at 60 degrees to produce aldehyde groups
schiff reagent reacts with aldehyde groups = magenta DNA
purpose ; demonstrate DNA
sources of error for feulgen
bouin fixative will prehydrolyse DNA
too long in HCL = false neg
methyl green - pyronin Y fixative and control tissue
fixative - NBF
control= contains plasma cells
principle and purpose of methyl green - pyronin y
principle : DNA is more polymerized and stains with methyl green RNA is less polymerized and stains with pyronin
purpose; to differentiate DNA & RNA and ID plasma cells
Methyl green- pyronin Y results
DNA- green/blue
RNA- red
goblet cells - green
plasma cells - red
nuclei - green/ blu e
background - pink
sources of error for methyl green
acids and some fixatives will cause depolymerization of DNA resulting in loss of ability to bind methyl green and no differentiation
May Grunwald Giemsa fixative, control
fixative - zenker or B5
control - spleen
May Grunwald GIemsa may be used for…
bone marrow
- hematopoietic tissue
