Lab Flashcards
Describe the key steps to determining a PCV
Gloves worn.
blood collected into EDTA tube.
Sample inverted gently, to mix
Microhaemocrit performed; capillary tubes centrifuged fro rapid deterimated PCV. Plain capillary tubes placed into blood sample at an angle and filled 3/4 full by capillary action.
finger placed over the top of the tube or you can keep the tube horizontal
Capillary tube removed from samples
Capillary tube wiped clean with a tissue
One end is plugged with soft clay sealant
Capillary tube then placed into a centrifuge with the lcay plug against the rim, should be balanced
Lid closed and locked
Centrifuge set at 10,000 RPM for 5 minutes
Waste disposed
What setting is a centrifuge required ot be at for PCV?
10,000 RPM for 5 minutes
Explain how a hawksley reader is used
Capillary tubes placed into reader slot with sealed end downwards
The top of the seal is aligned with the zero line on the reader
The tube holder is then moved across until the top of the plasma is lined up with the 100% line on the reader
The adjustable line is moved to intersect the top of the RBC layer
Record the PCV reading as a percentage
What are the normal values for PCV?
Dog, 37-55%
Cat, 24-45%
Explain how a refractometer is used to determine specific gravity
Gloves are worn
The refractomere is first calibrated with 2-3 drops od distilled water.
The refractomer is held up to a light source and you look down the eyepiece.
The SG is adjusted to 1.000 in the scale.
The cover is closed and the surface dried with a tissue.
The urine samples is invereted, to mix
1-2 drops of the sample is then pipetted onto the prism surface.
The SG scale is then read
The prism is the rinsed and dried
Any hazardous waste should be disposed in the clinical waste bin
Reading is recorded
What are the normal values for specific gravity?
Dog, 1.015-1.045
Cat, 1.020-1.040
What are the 2 parts of a blood count?
Quantitative examination and qualitative examination
What are the 3 layers of a PCV?
Plasma, buffy coat, RBC’s
What are the 3 different staining methods?
Giesma, leishmans and diff-quick
How is a giesma stain performed?
‘fix’ slide by dipping in methanol for 1 minute
Flood slide with diluted giesma stain and allow for stain to act for 15mins
Carefully rinse of any excess stain with distilled water
Allow to dry at room temperature
How is a leishamans stain performed?
Flood slide with leishsmans stain and leave for 2-3mins
Add twice the amount of stain volume of buffered sitilled water pH 6.8 and mix genty. Allow this to act for 15mins
Drain and dry at room temperature
How is a diff-quick stain performed?
Prepare small pots of each solution - deep enough to dip a slide complelty
Dip dried blood smear into solution A (blue) for 5X1 secs. Shake off any excess
Dip into solution B (red) for 5X1secs shake off excess
Dip into solution C (Purple) for 5X1 secs. Shkae off excess
Carefully rinse with distilled water and allow to air dry
