Exam 1 Lab Stains

Question 1

H&E (hematoxylin + eosin)

Answer 1

-Type: acidic-basic
(2 counterstains
-general-purpose & overview; picks up everything stained by hematoxylin or eosin
-stains nothing a neutral charge like lipids and carbs
-most common stain for LM

Question 2

Hematoxylin

Answer 2

-type- basic
-stains- basophilic (acidic) structures;
these are anions
-Color- basophilic structures: blue
-Examples - DNA, RNA, nucleus, RER,
ribosomes, GAGs
-Doesn’t stain- neutral or positive

Question 3

Eosion

Answer 3

-type-acidic
-stains- acidophilic (basic) structures;
these are cations
-color- acidophilic structures: pink to deep red
(depending on charge intensity)
-examples- most cellular proteins,
collagen fibers, RBCs
-doesn’t stain- neutral or negative

Question 4

Metachromatic Stains (touledine, methylene blue)

Answer 4

-type- basic and metachromatic
-stains - all basophilic (acidic) structures (all
anions); concentrated negative
charges stain a different color
-color- basophilic structures = blue; highly
concentrated negative charges =
purple or dark red-purple
-examples- ribosomes, nuclei = blue;
GAGs = purple or dark redpurple
-what is doesn’t stain- structures with a neutral OR
positive charge

Question 5

PAS

Answer 5

-specific
-complex carbs
-magenta and dark pink
-glycogen, glycoproteins, glycolipids, mucin, basement membranes

Question 6

Osmium

Answer 6

-specific
-lipids
-brownish black
-cell & organelle membranes,
fat droplets in cells, myelin
sheath surrounding axons
-used in LM &
also the main
stain for TEM

Question 7

Silver

Answer 7

-specific
-DNA and reticulin, collagen
-black
-doesn’t stain anything that isnt reticulin

Question 8

Prussian Blue

Answer 8

-specific
-iron deposits
-blue