Detection Methods

Question 1

Performed using touch preparations

Answer 1

Tissues (smear)

Question 2

Sample that Must be rolled back and forth across a dry, clean slide

Answer 2

Swabs

Question 3

Aspirates or body fluid Prep if high number of organisms are expected and if the specimen is thick

Answer 3

Single-drop smear

Question 4

Aspirates or body fluid Prep if a small number of organisms is expected

Answer 4

Centrifuged smear

Question 5

Aspirates or body fluid Prep used for low-volume specimens

A drop is placed on slide and allowed to dry. Another drop is placed on top of dried smear

Answer 5

Layered Smear

Question 6

Aspirates or body fluid Prep where an aliquot of the specimen is spun directly into a slide

Answer 6

Cytocentrifuged smear

Question 7

May be added to CSF to help cellular materials adhere to the slide

Answer 7

Albumin

Question 8

May be added to extremely mucoid specimens

Answer 8

Mucolytic

Question 9

What is gram stain?

Answer 9

A staining method that places bacteria into one or two groups (g+,g-) and determines g/s characteristic

Question 10

Gram stain reagent contact times:
Crystal violet
Gram’s iodine
Acetone-alcohol
Safranin Red

Answer 10

1 min
1 min
3-5 seconds, rinse with water
1 min

Question 11

G/S Primary stain

Answer 11

Crystal violet

Question 12

G/S mordant

Answer 12

Gram’s iodine

Question 13

G/S decolorizer

Answer 13

Acetone-alcohol

Question 14

G/S counterstain

Answer 14

Safranin red

Question 15

G+ cell wall color after gram stain

Answer 15

Purple

PoPu

Question 16

G- cell wall after gram stain

Answer 16

Pink

NePu

Question 17

Color of G- cell wall when not decolorized

Answer 17

Purple

Question 18

What does gram stain have that acid-fast stain does not have?

Answer 18

Mordant

Question 19

Acid-fast stain is primarily used to detect…

Answer 19

Mycobacterium species (TB)

Question 20

Fuchsin Stain that is also known as the cold method; uses a higher concentration of detergent to facilitate staining

Answer 20

Kinyoun method

Question 21

Fuchsin stain that is also known as the hot method; uses heat to facilitate staining

Answer 21

Ziehl-Neelsen Method

Question 22

Acid-Fast Stain Contact Time:
Carbolfuchsin
Acid-alcohol
Methylene blue

Answer 22

5 min., flame/steam, rinse, a few min., rinse

Decolorize until no more stain comes off/ rinse water

1 min., rinse, dry, examine

Question 23

What is the purpose of carbolfuchsin in acid fast stain?

Answer 23

Primary stain

Question 24

What is the acid-fast stain decolorizer

Answer 24

Acid-alcohol

Question 25

What is the purpose of methylene blue in acid fast staining?

Answer 25

Counterstain

Question 26

Acid-fast cell wall will appear ____ after staining

Answer 26

Red

Question 27

Non acid-fast cell wall will appear ___ after staining

Answer 27

Blue

Question 28

Fluorochrome stain that stain acid-fast organism fluorescence yellow or orange under a fluorescent microscope

Answer 28

Auramine-rhodamine

Question 29

Used to observe metachromatic granules in corynebacterium diphtheriae

Answer 29

Methylene blue

Question 30

Fluorochrome dye that stains both g+ g- organisms both living and dead

Answer 30

Acridine orange

Question 31

To determine the biological activity of microorganisms including motility or reactions to certain chemicals or serologic reactivity in specific antisera

Answer 31

Saline mount

Question 32

Uses slide but with deeper field of focus (because of depression slide) and without the distorting effects from weight of coverslip Generally used to observe motility

Answer 32

Hanging-drop method

Question 33

Used to visualize organisms that are invisible by brightfield microscopy and stain only with great difficulty Useful in demonstrating spirochetes

Answer 33

Darkfield examination

Question 34

Assess quality of sputum samples

Answer 34

Book page 18

Question 35

Culture medium that contains no agar or any hardening or solidifying agents

Answer 35

Liquid

Question 36

Agar percentage of semi-solid culture media

Answer 36

0.5-1.0%

Question 37

Culture medium that contains 2-3% agar

Answer 37

Solid

Question 38

Polysaccharide extract of seaweed/algae

Answer 38

Agar

Question 39

Culture medium that exact composition is known. Commercially prepared

Answer 39

Synthetic

Question 40

Culture medium thats exact composition is not known. Meat extract broth

Answer 40

Non-synthetic

Question 41

Culture medium made up of living cells

Answer 41

Cell culture

Question 42

Uses petri dishes

Answer 42

Plated media

Question 43

Use sterile test tubes

Answer 43

Tubed media

Question 44

Culture media that supports most non-fastidious bacteria

Answer 44

Non-selective media

Question 45

Culture media that supports the growth of one type of bacteria and not the other. Has inhibitory substances

Answer 45

Selective media

Question 46

Allows grouping of bacteria on the basis of different characteristics displayed on the medium. May be Selective or non-selective

Answer 46

Differential medium

Question 47

Designed to isolate fastidious bacteria. Has growth enhancers

Answer 47

Enriched media

Question 48

Designed to encourage growth of small numbers of a particular organism while suppressing the other flora present in the specimen

Answer 48

Enrichment broth (selective enrichment)

Question 49

Prevents replication while keeping bacterial cells viable

Answer 49

Transport media