Para Lab - Quiz 1 Flashcards
– most common specimen
stool sx
amount of stool collected (Formed)
2-5 g
about size of walnut or thumb
must be labelled with
Name
Age
Date and time of collection
how many stool specimens are collected in different days to increase chances of detecting the parasite
3
stool sx must be accompanied with
a lab request
brown color of stool due to
stercobilin
• Gross abnormalities – presence of abnormal structures such as
Mucus
o Pus
o Proglottids (Segment of a tapeworm)
o Blood
uses iodine and saline wet preparations for screening purposes
DFS
for detection of helminths (parasitic worms) & protozoans
DFS
For detection of trophozoite and cyst stages
DFS
Disadv of DFS
not sensitive because of very small amount of Sx used
can hide fecal organisms
Fecal debris
ADV of conc technique
-advantage: increases the chances of parasite detection because a larger amount of stool is used
DISADV of conc technique
-disadvantage: cannot preserve or detect trophozoites because they are easily destroyed
2 methods of conc technique
flotation
sedimentation
used for small eggs or cysts that tend to float
flotation
-principle of flotation
all eggs and cysts will float
flotation not suitable for protozoans but useful for demonstration of helminthic eggs
brine flotation
-Sp Gr of brine solution
= 1.20
measures specific gravity
Refractometer
Advantages of brine
Inexpensive
• Applicable in field work
Disadvantages of brine
Badly shrunken morphology of some eggs and cysts
Eggs of Clonorchis and Opistorchis do not float
useful for: recovery of protozoan cysts and helminth eggs
ZnSO4 flotation
sp gr in zinc sulfate flotation
Sp Gr = 1.18 – 1.20
ZnSO4 flotation NOT useful for
- Large trematode eggs
- Some tapeworm (cestode) eggs
- Ascaris lumbricoides unfertilized eggs
useful for detection of Cryptosporidium
Sheather’s Sugar Flotation
Solution added in Sheather’s Sugar Flotation
sucrose-phenol solution
used for heavy or large eggs or cysts
sediments
FECT meaning
Formalin Ether Concentration Technique
FECT Components
Components:
– preservative/fixative
10% formalin
FECT Components
removes fecal fats
-difficult and dangerous to handle, highly volatile
ether
FECT Components
to strain fecal suspension
gauze
FECT Components optional only (done for better visualization
Lugol’s iodine
FECT Components
removes fecal debris
conical tube
a substitute for 10% formalin but may destroy Blastocystis hominis
distilled water
susbtitute for ether
ethyl acetate
4 Layers that will be Formed in sedimentation (from top to bottom)
- Ether
- Debris
- Formalin
- sediment
- Used for quantitating helminth eggs
- Used to determine intensity of infection (↑ eggs, ↑ intensity of infection)
- results expressed as EPG or eggs per gram
kato-katz technique
another name of kato-katz
cellophane technique
KK components
pleasing to the eyes; soaked overnight in glycerol
Green cellophane
sub for green cellophane
substitute: 3% Aqueous Malachite Green or 3% Methylene Blue Stain + transparent cellophane
KK components
acts as a clearing agent to be able to view the Sx clearer
50% glycerol –
KK components
calibrated
template
template thickness and diameter
thick: 1.5 mm
dia: 6mm
KK components
removes large fecal debris for easy viewing
Wire mesh
KK components
– used to evenly distribute/spread stool
-
Rubber stopper/cork
sub for rubber stopper or cork
substitute: mineral bottle cover
KK components
used in pressing the wire mesh and scraping of the sieved stool
Popsicle stick
hastens the clearing process
Heat (40C) or direct sunlight
