Microscope, Gram stain, Acid Fast, FITC, Molecular Assay

Question 1

Number of bacteria needed for broth turbidity (visible to naked eye)

Answer 1

10^6 or 1,000,000 bacteria/mL

Question 2

Light Microscopy Sensitivity

Answer 2

10^5 or 100,000 bacteria/mL

Question 3

Fluorescent Microscopy Sensitivity

Answer 3

10^4 or 10,000 bacteria/mL

Question 4

Microscopy where bacteria are seen

Answer 4

Bright-field, Digital, Fluorescence, Phase Contrast, Limited use of Dark Field

Question 5

Microscopy where fungi are seen

Answer 5

Bright-field, Digital, Fluorescence, Phase Contrast

Question 6

Microscopy where parasites are seen

Answer 6

Bright-field, Digital, Fluorescence, Phase Contrast, Electron (Limited use)

Question 7

Microscopy where viruses are seen

Answer 7

Digital, Fluorescence, Electron

Question 8

Most used smear in bright-field

Answer 8

Fixed smear

Question 9

Microscopy for aquatic environmental bacteria

Answer 9

Digital Holographic Microscope (Digital Microscopy, 100x greater resolution than bright-field)

Question 10

Specific detection of microbes by tagging (probes, enzymes)

Answer 10

Fluorescence Microscopy

Question 11

Visualization of living and non-living cells in unfixed smear/wet smear

Answer 11

Phase Contrast Microscopy

Question 12

Microscopy only for spirochetes

Answer 12

Dark Field Microscope

Question 13

Non-conventional microscopy for diagnostic purposes

Answer 13

Electron Microscope

Question 14

Gram-positive bacteria color

Answer 14

Purple

Question 15

Gram-negative bacteria color

Answer 15

Pink

Question 16

Gram staining procedure

Answer 16

Fix with methanol or heat, apply primary stain (10 to 30 seconds), rinse with tap water, apply mordant (twice as long as primary stain), rinse with tap water, apply decolorizer (10 seconds or less), rinse immediately with tap water (longer for thicker smears), apply counterstain (30 seconds), rinse with tap water, blot dry with paper towels, bibulous paper, or air dry (air dry for delicate smears).

Question 17

Primary stain for Gram stain

Answer 17

Crystal violet

Question 18

Mordant for Gram stain

Answer 18

Gram’s iodine

Question 19

Decolorizer for Gram stain

Answer 19

Alcohol and/or acetone

Question 20

Counterstain for Gram stain

Answer 20

Safranin

Question 21

Ziehl-Neelsen Acid-fast positive bacilli color

Answer 21

Red (or bright red or pink) against blue or green background

Question 22

Ziehl-Neelsen Acid-fast negative color

Answer 22

Same as background (blue or green)

Question 23

Ziehl-Neelsen Primary stain

Answer 23

Carbolfuchsin red

Question 24

Ziehl-Neelsen Decolorizer

Answer 24

3% HCl in 95% ethanol (HCl, alcohol)

Question 25

Ziehl-Neelsen Counterstain

Answer 25

Methylene blue or malachite green

Question 26

Ziehl-Neelsen Procedure

Answer 26

Fix smear (60°C for at least 10 minutes), apply primary stain, heat to almost boiling (should steam), sit for 5 minutes (do not allow to dry out), wash slides with distilled water, apply decolorizer (1 minute), wash with water, apply counterstain (1 minute), wash with distilled water, air dry (do not blot), examine under 400x for screening, confirm suspicious organisms at 1000x magnification using an oil-immersion lens.

Question 27

FITC Interpretation (no apple-green fluorescence)

Answer 27

Negative

Question 28

FITC Interpretation (faint yet unequivocal apple-green fluorescence)

Answer 28

1+

Question 29

FITC Interpretation (apple-green fluorescence)

Answer 29

2+

Question 30

FITC Interpretation (bright apple-green fluorescence)

Answer 30

3+

Question 31

FITC Interpretation (brilliant apple-green fluorescence)

Answer 31

4+

Question 32

Nucleic Acid Hybridization

Answer 32

Filter/Membrane hybridization, Sandwich hybridization, In Situ Hybridization

Question 33

Filter/Membrane Hybridization Examples

Answer 33

Southern Blot, Northern Blot

Question 34

In Situ Hybridization Examples

Answer 34

FISH, PNA-FISH

Question 35

Signal Amplification Hybridization

Answer 35

Branched DNA (bDNA), Hybrid Capture, Cleavase-Invader (Isothermal Cycling Probe Technology)

Question 36

Nucleic Acid Amplification (PCR-Based)

Answer 36

Conventional/End-point PCR, Real-Time PCR, RT-PCR, Real-Time RT-PCR, Nested PCR, Digital PCR, Multiplex PCR

Question 37

Nucleic Acid Amplification (Non-PCR-Based)

Answer 37

Nucleic Acid Sequence-Based Amplification (NASBA), Transcription-Mediated Amplification (TMA), Strand Displacement Amplification (SDA)

Question 38

Nucleic Acid Sequencing

Answer 38

Sanger Sequencing, Pyrosequencing, Next-Generation Sequencing (Massive Parallel Sequencing)