SG Protein Marker_Staining Pattern

Question 1

AQP5

Answer 1

Highlights the apical (inner) membrane of serous acinar cells and intercalated ducts

Question 2

ACTA2 (SMA)

Answer 2

Shows a basket-like mesh or “fingers” wrapped around the acini.

Question 3

KRT18

Answer 3

Stains the cytoplasm of the inner lining of the entire duct system.

Question 4

MUC5B

Answer 4

Fills the large mucin droplets within the cell body; often very bright.

Question 5

α-Amylase

Answer 5

Targets the secretory granules in the cytoplasm of protein-rich cells.

Question 6

p63

Answer 6

Strictly nuclear; useful for counting cells or identifying the outer layer.

Question 7

KRT5 / KRT14

Answer 7

Stains the cytoplasm of the “anchoring” cells at the bottom of the ducts.

Question 8

Lgr5

Answer 8

Marks undifferentiated cells primarily located within the ductal niches.

Question 9

ZO-1

Answer 9

Apical-lateral membranes; appears as a sharp “outline” where secretory or ductal cells meet.

Question 10

BPIFB2

Answer 10

Cytoplasmic/Granular; marks specific lipid-binding and antimicrobial proteins in the saliva.

Question 11

BPIFA2

Answer 11

Cytoplasmic; formerly known as SPLUNC2, it is a major protein secreted by serous acini into the lumen.

Question 12

MIST1

Answer 12

Nuclear; a master transcription factor that tells a cell to become a mature, “ready-to-secrete” acinar cell.

Question 13

MUC7

Answer 13

Cytoplasmic/Secretory; stains the low-molecular-weight mucins specifically found in saliva.

Question 14

P16

Answer 14

Nuclear/Cytoplasmic; usually a marker for cellular “aging” or stress, often used to check for gland degradation.

Question 15

HSD11B2

Answer 15

Cytoplasmic; involved in steroid metabolism, specifically highlighting the electrolyte-modifying segments of the duct.