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Diagnostic Laboratory Procedures
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Microscope Use Objective lenses 4x, 10x, and 40x
Oil-immersion is used occasionally A mechanical stage is necessary to view slides thoroughly
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Microscope Use Viewing area = field
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Microscope Use To scan a slide use 4x to focus, then move to 10x
Scan back and forth overlapping each field
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Microscope Use Scanning pattern
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Microscope Use Debris can be closely examined under high power
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Sample Collection The animal owner will most often collect the stool sample.
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Sample Collection The sample should be fresh since some parasite eggs become unrecognizable as the feces ages.
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Sample Collection If a fresh sample cannot be obtained, one can be refrigerated, but for no longer than 24 hours.
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Methods Gross exam - used to observe outward characteristics of the sample.
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Methods Gross exam - Several abnormalities can be seen with the naked eye.
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Methods Gross exam - observe and record • color and consistency
• blood and mucus • age of sample • presence of adult parasites
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Methods - the fastest and simplest method of diagnosing parasitism.
2. Direct smear - the fastest and simplest method of diagnosing parasitism.
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Methods 2. Direct smear - A small amount of feces is mixed with water and applied directly to a slide.
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Methods 2. Direct smear - The main disadvantage of this technique is that a small sample may not contain any parasite eggs.
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Methods 2. Direct smear - This method also leaves debris on the slide.
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Methods 3. Floatation - the most commonly used procedure for diagnosing parasitism.
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Methods 3. Floatation - techniques using this method:
- simple floatation - use of a centrifuge - Fecalyzer
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Methods 3. Floatation Fecalyzer - uses a solution (zinc sulfate or sodium nitrate) that has a specific gravity greater than the specific gravity of most parasite eggs
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Methods - is commonly used for eggs that have a high specific gravity
4. Sedimentation - is commonly used for eggs that have a high specific gravity
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Methods 4. Sedimentation - The high specific gravity of these eggs makes it difficult to use floatation techniques without distorting them.
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Methods - Sedimentation allows eggs to sink to the bottom.
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Debris may be easily confused with parasite eggs.
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Common Debris: hair plant material air bubbles fat epithelial cells
pollen grains
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