Laboratory: Examination of Parasites in Blood Specimen

Question 1

Capillary blood should be free-flowing and not contaminated with the alcohol used to cleanse the puncture site. True or False?

Answer 1

True

Question 2

Anticoagulants do not cause distortion to the staining process and subsequent. True or False?

Answer 2

False, it does cause some distortion.

Question 3

If malaria is suspected, it is best to prepare smears within _ hour of collection

Answer 3

1 hour

Question 4

Methods of Blood Examination for Venous Blood Sample

Answer 4

Knott’s Concentration Method
Membrane Filtration Method

Question 5

Methods of Blood Examination for Finger-Prick Blood Sample

Answer 5

Wet/Fresh Preparation
Capillary Tube Method
Stained Smears

Question 6

This method is designed to concentrate blood specimens suspected of containing low numbers of microfilariae

Answer 6

Knott’s Concentration Method

Question 7

Supernatant is discarded and sediment is smeared and stained with Wright stain in Knott’s Concentration Method. True or False?

Answer 7

False, it is stained with Giemsa

Question 8

How many mL of blood is needed in Membrane Filtration Method?

Answer 8

1 mL

Question 9

How many mL of distilled water is added in Membrane Filtration Method?

Answer 9

10 mL

Question 10

What is the filter used where the combined blood and distilled water pass through?

Answer 10

Swinney filter

Question 11

What stain is used in Membrane Filtration Method?

Answer 11

Dilute Giemsa

Question 12

Types of membrane filters used for MFM?

Answer 12

Millipore
Nucleopore

Question 13

What is the most sensitive method?

Answer 13

Membrane Filtration Method

Question 14

Species identification is not possible in what method?

Answer 14

Wet or Fresh Preparation

Question 15

In Buffy Coat Film, what is the color of the nuclear material and cytoplasm of L. donovani?

Answer 15

Dark red-purple
Light blue

Question 16

What can be detected in large mononuclear cells found in buffy coat?

Answer 16

L. donovani
Trypanosomes
Histoplasma capsulatum

Question 17

What is the pre-coating of capillary tube in QBC?

Answer 17

Acridine orange
Potassium oxalate

Question 18

What can be found in buffy coat?

Answer 18

Lymphocytes
Monocytes
Granulocytes
Platelets

Question 19

This is the stain of choice because it provides optimal detail of intracellular malarial parasites

Answer 19

Giemsa stain

Question 20

This stain already contains alcohol so fixation is not required before staining

Answer 20

Wright’s stain

Question 21

This stain is used to improve visibility of the microfilarial sheath

Answer 21

Delafield’s Hematoxylin stain

Question 22

Percentage of formalin and acetic acid that dehemoglobinize thick films?

Answer 22

2% formalin
1% acetic acid

Question 23

If whole blood is used: examiner should continue stirring about _ seconds to prevent the formation of fibrin strands

Answer 23

30 seconds

Question 24

Are thick films used for screening purposes? True or False?

Answer 24

True

Question 25

This smear is used routinely used for parasite identification to the species level

Answer 25

Thin Films/Smear

Question 26

Name of method done using two clean glass slides to produce thick on one end and thin and feathery at the other end

Answer 26

Wedge method Push slide technique

Question 27

Condition of blood where the morphology of both parasites and infected RBCs may not be typical

Answer 27

Anticoagulated blood from an hour ago

Question 28

Which is examined first, thin smear or thick smear?

Answer 28

Thin smear

Question 29

pH level of buffer used in Giemsa staining

Answer 29

pH 7.0-7.2

Question 30

Ratio of Giemsa to buffer

Answer 30

1 part Giemsa stock : 10-50 parts buffer

Question 31

Lack of _ fixation allows for lysis of red cells in the Giemsa staining solution.

Answer 31

Methanol

Question 32

How many fields before a film is reported as negative?

Answer 32

100-300 fields Preferred is 100, only 300 for non-immune patients

Question 33

If 200 leukocytes were counted; no. of parasites counted is multiplied by?

Answer 33

40

Question 34

if 500 leukocytes were counted; no. of parasites counted is multiplied by?

Answer 34

16

Question 35

Color of Leishmania, trypanosome, malaria and Babesia nuclear structures when stained

Answer 35

Red

Question 36

Color of cytoplasm when stained

Answer 36

Blue

Question 37

Color of Schiffer's dot when stained

Answer 37

Red

Question 38

Color of nuclei when stained

Answer 38

Blue to purple

Question 39

Color of sheath when stained

Answer 39

Clear, may not stain

Question 40

Color of RBC when stained

Answer 40

Pale red

Question 41

Color of WBC when stained

Answer 41

Purple

Question 42

Color of neutrophilic granules when stained

Answer 42

Pink-purple

Question 43

Color of eosinophilic granules when stained

Answer 43

Purple-red

Question 44

Smear used for screening parasites, detecting mixed infections

Answer 44

Thick Film/Smears