Module 1: Basic Diagnostic Concepts Flashcards
How to choose a technique?
Well, depends on the parasite. However, consider:
Host, Clinical presentation, Age of host and Exposure.
What are the common techniques?
For parasite identification
- Fecal flotation (centrifugation)
- Bearmann
- Fecal smear
- Quantification (equine, ruminants, production)
- Soil or pen ropes
- Muscle biopsy or histopath of tissues
- Sedimentation
- PCR
What is the most common technique used per the professor?
Double centrifugation flotation assay
This method has a two step proccess of water washing and suggar float.
What magnification should we use to scan a slide?
Whathever the fk u want!
Its 10X. It will take forever to scan at a higher mag.
Which parasites can cause respiratory signs on a cat?
Heart Worms and Lung Worms
Is it rare to identify larva on a flecal float?
Yes!
Almost always, you only see ova. However, sometimes you can see a larva.
Double Centrifugation
(Overview of what it is)
- Wash fecal sample and pellet eggs
- Floating the eggs
- Microscopic examination of eggs
- Specific gravity of species
Protocol for Double Centrifugation
- Mix feces (1grm) with around 7 mL of H2O (Mix well)
- Strain the mix to remove particulates (cheese cloth, metal strainer and others).
- Let the brown water precipitate
- Remove excess of water
- Add flotation solution to fecal pellet (fill up to 1mm from the top)
- Centrifuge sample
- Add a bit more solution to form meniscus
- Add coverslip
Why pay attention to the big G?
Gravity
Because of physics. Eggs typically float if the solution is 1.26 or greater in density.
Eggs are typically ( >1.0 - < 1.26 ) in density.
Where are the eggs located after the water wash step?
Because eggs are of a higher density than water, the ova should be located in the precipitate or the bottom of the sample.
Name the kids of solutions used for fecal floats?
- NaCL
- Zinc sulfate
- Sodium nitrate
- Sheather’s sugar or Sugar
Sugar holds ova for longer!
Do you dilute float solution to make more?
Hell naa mother fker! Leave that as it is! Sooo False you stupid!
Do you use hydrometer or refractometer to measure SG of solution?
Specific Gravity
Hydrometer
Used for density
Why would you use different solutions for fecal floatation?
Because sometimes, specific gravities are needed to preserve the eggs or find them.
Like everything, it depends of what you are looking for.
Centrifugation instructions
- Spin for 5 minutes (do not stop)
- Speed (400 - 1000 x g)
