thick and thin blood smear

Question 1

true or false:
The Philippines is epidemic to Malaria

Answer 1

false - it is endemic.
[hence making it accurate diagnosis crucial for effective treatment and control]

Question 2

what is the essential diagnostic tools for Malaria

Answer 2

thick and thin blood smear
*it is the standard test for detection of malaria

Question 3

Involves applying a larger drop of blood to a slide, allowing it to dry without spreading thinly

Answer 3

thick blood smear

Question 4

Is prepared by spreading a small drop of blood into a thin layer on a slide.

Answer 4

thin blood smear

Question 5

briefly explain in both thick and thin smear
- purpose
- preparation method
- staining process

Answer 5

THICK SMEAR
- screen presence of malarial parasite
- use large drop of blood (3 drops or 6uL)
- lysed/ dehemoglobinized RBC’s

THIN SMEAR
- allows for malarial species identification, quantification of parasitemia and recognition of different plasmodium stages
- use small drop of blood (1 drop or 2 uL)
- fixed RBCs in methanol

Question 6

blood collection methods

Answer 6

1. capillary puncture specimen: capillary blood
2. venipuncture with tube containing anticoagulant
   specimen: whole blood

Question 7

how to prepare thick and thin blood smear on the same slide

Answer 7

1. touch the blood drop with a clean slide
2. use the corner of another slide, spread the blood drop int te shape of a circle or a square of ~ 1cm^2
3. gently squeeza the patient’s finger again and touch the edge of a clean slide to the newly formed blood drop.
4. take the slide and hold the edge that has the blood drop at an ~ 45 degree against the surface of the first slide. wait until the spreads along the edge of the second slide
5. while holding the second slide at the same angle, rapidly and smoothly push the slide forward
6. write the identification no. on the slide and wait till the thick film is completely dry b4 staining it

Question 8

what are someo fthe common errors in preparing blood films

Answer 8

1. Drop of blood too large or too small.
2. Failure to keep the entire edge of the spreader slide against the slide while making the smear.
3. Chipped or dirty edge of spreader.
4. Slide contaminated with fat or grease.

[look at pics to refer]

Question 9

stain of choice

Answer 9

giemsa stain
→ A Romanowsky based stain
Two compositions: eosin, methylene blue
[meaning it uses a mix of dyes to color blood cells and parasites.]

2 components of the giemsa stain:
Eosin – stains the parasite nucleus RED
Methylene blue – stains the cytoplasm BLUE

Question 10

how do you prepare a thick and thin blood smear for staining

Answer 10

thin blood smear:
- Fix it with methanol before staining.

thick blood smear:
- Do not fix it with methanol. Instead, use acetic acid to remove hemoglobin. (dehemoglobinization).

Question 11

what equipment do u use to carefully drop the methanol

Answer 11

pasteur pipette

Question 11

specimen of choice

Answer 11

capillary blood (for anticoagulant)

Question 12

fixation method

Answer 12

rapid method:
use pasteur pipette - apply methanol on the thin film only.
8-10min

slow method:
dip the thin smear in container containing methanol for 2 seconds.
45-60min

Question 12

washing method in staining procedures

Answer 12

rapid method:
pour the H20 into the thin film end
do not pour stain directly off the slides
the metallic green surfaces scum will stick to the film - spoiling it for microscopy

slow method:
gently pur clean water into the tray to float off the iridescent scum
gently pour off the remaining stain and rinse with clean water

[Rapid method: Pour clean water into the container, not directly onto the slide.
Slow method: Gently pour clean water into the tray, then rinse the slide.]

Question 13

staining procedures

Answer 13

ppt