Laboratory Activity 13: MALARIAL SMEAR PREPARATION Flashcards
Systemic or blood-borne parasitic infections (such as malaria) are diagnosed by demonstrating the (?) of the responsible parasite(s) in a blood specimen.
diagnostic stage(s)
(?) are frequently satisfactory for screening purposes, particularly when malaria is suspected.
Thick smears
provide the best view of the malarial parasites in red blood cells and are recommended for species identification.
Thin smears
smears typically have a much higher concentration of parasites than thin smears.
Dehemoglobinized thick
are primarily used when parasites are few in number or when thin smears are negative.
Thick smears
The advantage of the thick smear is increased ability to detect the (?); the disadvantage is that the red blood cells have been (?) and it is not possible to assess the morphology of parasites that are detected.
malarial parasites
lysed
Preparation of thick blood smear:
1. Perform a skin puncture and place (?) of blood onto one end of a clean microscope slide.
2. Using the corner of a second clean microscope slide as a stirrer, combine the contents of the three
drops of blood by thoroughly mixing and spreading to a (?) approximately the size of a dime or
nickel.
3. Let the slide (?).
4. Remove the hemoglobin by immersing the slide in a buffer solution before staining or directly during (?).
5. Stain with (?). Note: OMIT FIXATION
6. Air dry and (?) under the microscope
three small drops
circular film
air-dry
Giemsa staining
Wrights or Giemsa
examine
Preparation of thin blood smear:
1. Procedure follows the conventional (?). Air dry.
2. Fix with
3. Stain with (?). Air dry
4. (?) under the microscope.
2-glass slide method or wedge method
methanol
Wrights or Giemsa stain
Examine smears
Note: If malaria is suspected, it is best to prepare smears within (?), because storage of blood for a longer period leads to distortion and possible loss of malarial parasites.
1 hour of collection
