Transcript Creating the Blood Smear

Packed Cell Volumes
Total Proteins
Blood Smear Prep
PCV (Packed Cell Volume)
In the CBC, we determine the
number of RBC’s in several
different ways. The quickest
and easiest is called the
hematocrit, also referred to as
the packed cell volume (PCV).
The hematocrit or the packed
cell volume will tell you if the
animal is dehydrated or anemic.
Whole blood is collected in an
anticoagulant, EDTA, and
placed in a capillary tube.
Microhematocrit tubes should
be filled to the designated line,
with one ended plugged with
clay sealant
 A blood sample should be spun in a
microhematocrit centrifuge for 2-5
minutes.
 Lie the tube in the centrifuge with plugged
end to the outside. *Note the number of
your slot. Ensure that a balancing
hematocrit tube is placed opposite,
either by someone placing their tube
there, or by adding an empty tube
 The cells are heavier than the plasma and
are compacted at one end of the tube.
The bottom of the RBC layer
should be at the zero line and the
top of the plasma on the top line
(page 37 Fig 2-7)
PCV is determined as the
percentage of the cellular portion
relative to the total amount of
blood in the tube
Plasma Evaluation
 Plasma color and transparency may be
helpful in the determination of a
diagnosis and should be recorded .
 Normal plasma is clear and a pale
straw –yellow color
 Cloudy Serum = lipemic
 Reddish Tinge = hemolyzed
 Yellow = Icteric (liver dz)
 If the serum is anything but clear, a
falsely elevated total protein will result.
 Page 36
Plasma Protein Concentration or
Total Protein / Total Solids
Plasma Protein concentrations
estimation by refractometry is an
important component of the CBC
in all species
The plasma used to determinate
the TP is collected by breaking
the hematocrit tube just above
the buffy coat- plasma interface.
The plasma is allowed to
flow onto the refractometer
prism.
Page 37 fig 2-9
Blood Film / Smears
The blood film is used to perform
the differential WBC count; estimate
platelet numbers; and evaluate the
morphological features of WBCs,
RBCs and platelets.
Wedge smears are prepared by
placing a small drop of blood on a
clean glass microscope slide
Diff Quick Stain
Always stain using the
lightest to darkest stain.
Dip each slide 10-12 times
Remember which side of
your slide is up.
Rinse off stain using a
gentle stream of water.
Allow slide to air dry.
Overstaining of a slide