Staining

Question 1

used to distinguished fungi in thick mucoid specimens or in samples that contain keratinous material such as skin, hair, and nails.

Answer 1

10% KOH

Question 2

alternative to KOH

Answer 2

NAOH with glycerin

Question 3

to β-1,3 and β-1,4 polysaccharides specifically cellulose and chitin of fungal cell walls

Answer 3

calcofluor white

Question 4

color of fungal elements in calcofluor white

Answer 4

bluish white to green

Question 5

exhibit a characteristic peripheral cyst wall staining with an intense “double parenthesis-like” structure in CW

Answer 5

P. jirovecii

Question 6

Yeast cells are differentiated from P. jirovecii in CW by

Answer 6

budding and intense staining

Question 7

interference that fluoresces strongly with CW

Answer 7

cotton fiber

Question 8

stain used in other specimens such as BAL or CSF

Answer 8

Rapid Giemsa-like (Diff-Quik)

Question 9

stain used to differentiate Leishmania and Histoplama

Answer 9

Rapid Giemsa-like (Diff-Quik)
L has kinetoplast, H does not

Question 10

used in detection of encapsulated microorganisms of C. neoformans in CSF.

Answer 10

Colloidal carbon wet mounts (India ink, nigrosin)

Question 11

Commonly used for the microscopic examination of fungal cultures by tease or tape preparation.

Answer 11

Lactophenol cotton blue (LPCB)

Question 12

components of LPCB and purpose

Answer 12

Lactic acid - clearing agent , preserving the fungal structures.
Phenol - killing agent
Glycerol - prevents drying
Cotton blue (Poirrier’s blue and aniline blue ) - provides color to the structures.

Question 13

Primarily used for the examination of heat fixed, or alcohol fixed bone marrow, buffy coat, and peripheral blood smears.

Answer 13

Giemsa stain

Question 14

Giemsa stains detect

Answer 14

intracellular H. capsulatum
fission yeast cell of Talaromyces marneffeium
trophozoite of P. jirovecii

Question 15

gram staining of yeasts and pseudohyphae

Answer 15

gram (+)

Question 16

gram staining of hyphae

Answer 16

gram (-)

Question 17

may decolorize in gram stain and appear either gram negative or stippled

Answer 17

Cryptococcus

Question 18

modified acid fast stains Nocardia

Answer 18

partially acid-fast (pink)

Question 19

Actinomycetes are negative in:

Answer 19

Modified acid-fast

Question 20

Used in detection of P. jirovecii in respiratory specimens viz. lung biopsy specimen imprints and BAL specimens

Answer 20

Toluidine blue O

Question 21

appearance of P. jirovecii Toluidine blue O

Answer 21

reddish blue/ dark purple cyst walls, often clumoed and crescent
no trophozoites

Question 22

species of Candida stains gold in this stain

Answer 22

Papanicolaou

Question 23

Mucopolysaccharide stain like India ink, does not detect all cases.

Answer 23

Alcian blue

Question 24

stains blue against a pink background in histological sections of tissue Toluidine blue

Answer 24

polysaccharide capsule of Cryptococcus

Question 25

Has advantage of allowing observation of natural pigments of fungi. best stain to demonstrate host tissue reaction and pigment of dematiaceous fungi.

Answer 25

Hematoxylin and eosin (H&E)

Question 26

Fungal cytoplasm and nuclei in H and E

Answer 26

pink, blue

Question 27

stains glycogen, so other tissue structures can have a similar appearance to yeast cells.

Answer 27

Periodic acid schiff

Question 28

Fungal stain of choice of many dermatopathologists.

Answer 28

Periodic acid Schiff (PAS)

Question 29

Periodic acid Schiff (PAS) Demonstrates this but not GMS

Answer 29

double-contoured refractile walls of Blastomyces dermatitidis

Question 30

Often stains fungi too densely to observe structural details.

Answer 30

Gomori methenamine silver (GMS)

Question 31

color of fungal elements in GMS

Answer 31

Pneumocystis jirovecii stain gray to black. Background is green.

Question 32

Stains mucin

Answer 32

Mucicarmine

Question 33

Mucicarmine is Useful for differentiating this from other fungi of similar size and shape when found in samples of tissue

Answer 33

c. neoformans (gatii)

Question 34

Detection of melanin of dematiaceous fungi and C. neoformans.

Answer 34

Fontana-Mason (FM)

Question 35

demonstrates the bacterial filaments of the actinomycetes, eg., Nocardia, Actinomadura.

Answer 35

Brown and Brenn (B&B)

Question 36

Specific method of detecting fungi in body fluids

Answer 36

Fluorescent antibody stain

Question 37

fluorescein-labeled Ab reacts with fungal antigen in cell wall.

Answer 37

Direct technique:

Question 38

unlabeled Ab complexes with fungal antigens. Fluorescein-labeled conjugate reacts with globulins attached to fungal antigens. Cell walls yellow-green.

Answer 38

Indirect technique

Question 39

Specific and highly sensitive. Can be used to detect and measure antibodies.

Answer 39

immunoperoxidase technique