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
