stains

Question 1

acidophilic

Answer 1

Structures that stain with eosin, a negatively charged dye that stains pink to red. Acidophilic tissue componenets have a net positive charge such as proteins (NH2+). Examples of acidophilic components: mitochondria (due to membrane proteins), Lysosomes (due to enzymes) erythrocytes (hemoglobin), collagen fibers, secretory vacuoles that contain proteins, and cytosolic proteins.

Question 2

aldehyde fuchsin

Answer 2

A stain that produces violet staining of elastic fibers, mast cell granules, gastric chief cells, beta cells of the pancreatic islets.

Question 3

basophilic

Answer 3

Tissue components that carry a net negative charge and therefore bind positively charged dyes such as hematoxylin. Basophilic tissue components include DNA, RNA (PO4) Proteoglycans, and GAGs (SO4, CO2). Examples of basophilic structures include: nucleus, nucleolus, and ribosomes.

Question 4

best’s carmine

Answer 4

A stain used for the demonstration of glycogen in tissues.

Question 5

bouin’s

Answer 5

A common fixative for light microscopy. It includes formalin, acetic acid and picric acid.

Question 6

formalin

Answer 6

A 37% aqueous solution of formaldehyde. The most common fixative agent used in light microscopy.

Question 7

glutaraldehyde

Answer 7

A dialdehyde used as a fixative, especially for electron microscopy. By its interaction with amino groups (and others) it forms cross links between proteins.

Question 8

lipofuchisn

Answer 8

Yellowish-brown pigment that accumulates in residual bodies (old lysosomes) in long-lived cells; e.g. in liver, kidney, adrenal, cardiac muscle, and/or ganglion cells of older people. Believed to be the oxidized lipid-containing residues of lysosomal digestion.

Question 9

metachromasia

Answer 9

The situation where a stain when applied to cells or tissues gives a color different from that of the stain solution; i.e., toluidine blue staining mast cell granules reddish purple. Metachromasia usually occurs when a basic stain binds to a polyanion in the specimen so that dye molecules are close enough for interactions to occur between them.

Question 10

oil red o

Answer 10

stains lipids red

Question 11

osmium

Answer 11

Osmium tetroxide stains unsaturated lipids dark brown or black (also acts as a lipid fixative)

Question 12

periodic acid-schiff (PAS)

Answer 12

Staining technique which stains glycogen and most carbohydrate-rich molecules magenta. Used to demonstrate basement membranes, glycocalyx, glycogen, etc.

Question 13

wright’s

Answer 13

A type of Romanovsky stain used for differential staining of blood cells; pink=erythrocytes, eosinophil granules; purple=leukocyte nuclei, basophil granules; blue=cytoplasm of monocytes and lymphocytes

Question 14

zenker’s

Answer 14

Zenker’s fixative=rapid fixative useful light microscopy. Based on a mixture of formalin and mercuric chloride.