Carbohydrate and Amyloid Stains

Question 1

What tissue element does Colloidal Iron, Alcian Blue, and Mucicarmine all demonstrate.

Answer 1

Mucin

Question 2

What one tissue type can be used as a control can for Colloidal Iron, Alcian Blue, and Mucicarmine.

Answer 2

Small bowel.

Question 3

Name 2 things that can be demonstrated with the Colloidal Iron Stain.

Answer 3

Mucin, mast cells, calcium salts, hyaluronic acid, and some fungi and forms of RCC.

Question 4

Why would a pathologist care about mucin production?

Answer 4

Enzyme deficiency diseases and many tumors produce mucin.

Question 5

True or False: The 2 main types of mucin are acid and neutral.

Answer 5

True

Question 6

Name a good counterstain for Colloidal Iron.

Answer 6

Neutral Red, Nuclear Fast Red, or Van Gieson because they contrast with Prussian Blue.

Question 7

Why do we use solutions of differing pH in the Alcian Blue stain?

Answer 7

Alcian Blue 1.0 and 2.5 stain different subgroups of acid mucins.

Question 8

True or False: The light blue color of the Alcian Blue stain comes from iron.

Answer 8

False. It comes from copper.

Question 9

What other carbohydrate stain is often paired with the Alcian Blue?

Answer 9

Periodic Acid Schiff. The AB-PAS will demonstrate both acid and neutral mucin.

Question 10

How does the colloidal iron stain work?

Answer 10

Ferric ions in a colloidal solution bind with acidic mucins. This forms blue deposits and is called the Prussian Blue reaction.

Question 11

Why doesn’t the mucin in Brunner’s glands of the duodenum stain with colloidal iron?

Answer 11

Brunner’s glands have NEUTRAL mucins. Colloidal iron stains ACID mucins. Brunner’s glands will stain with PAS.

Question 12

What stains neutral mucins?

Answer 12

Periodic-Acid Schiff.

Question 13

What color does the mucin in goblet cells stain with an ABPAS?

Answer 13

Purple. Also, magenta and blue separately. Goblet cells can contain both acid and neutral mucins, so the magenta of the PAS reaction and the blue of the alcian blue stain are both present, making some of the cells appear purple.

Question 14

How thick should you cut amyloid controls?

Answer 14

8-10 microns.

Question 15

Both patient and control tissue for the Congo Red stain should be cut at 8-10 microns. Why?

Answer 15

To be able to see the birefringence with a polarizing microscope.

Question 16

What color is amyloid with the Congo Red stain?

Answer 16

Pink-orange with a light microscope, apple-green with a polarizing microscope, and bright orange with a fluorescent microscope.

Question 17

Name an amyloid stain other than the Congo Red.

Answer 17

Crystal Violet and Thioflavin T, which is a fluorescent dye.