PBS Flashcards
Specimen used
EDTA blood
blood smears should be made within ___
2 hours
advantages of EDTA blood smear
- Multiple blood smears may be made.
- The blood smear may be prepared at a later time.
- EDTA prevents platelet clumping
disadvantages of EDTA blood smear
1) Platelet satellitosis
2) EDTA-induced platelet clumping
Platelet satellitosis results in
Pseudothrombocytopenia
Platelet satellitosis is corrected by
using 3.2% sodium citrate
platelet count x 1.1
EDTA-induced platelet clumping results in
1) Pseudothrombocytopenia
2) Pseudoleukocytosis
EDTA-induced platelet clumping is corrected by
using 3.2% sodium citrate
(platelet count x 1.1
WBC count x 1.1)
Best for evaluation of blood cell morphology
Anticoagulant-free blood
MOST FREQUENTLY USED blood film preparation
Manual Wedge Technique)
angle between two slides in Manual Wedge Technique)
30 - 45’ angle
if angle of spreader is too high > 45’
thicker smear
if angle of the spreader is too low < 30 ‘
thinner smear
size of drop of blood in blood film prep
2 - 3 mm
distance of drop of blood from label of slide
1 cm
if too low hct (Anemia)
angle should be raised
if too high hct (PV)
angle is lowered as low as 25’
scanning method from tail to head
Longitudinal
scanning method back & forth serpentine
Battlement
Characteristics of an IDEAL BLOOD SMEAR
Gradual transition from thick to thin area
2/3 to 3/4 the length of the film slide
Finger-shaped
Visible lateral edges
Without irregularities, holes, or streaks
Feather edge has rainbow appearance
Whole drop of blood is picked up and
spread
blood film prep technique that is excellent in WBC distribution
Coverslip technique
sometimes used for BM aspirate smeare prep
Coverslip technique
Automated Methods (blood film prep)
A.) Miniprep
B.) Centrifugal (Spinner) Type
C.) Coulter LH
D.) Sysmex SP-10
B.) Centrifugal (Spinner) Type uses ____ volume of blood
0.2mL
Both slide makers & slide stainers
Coulter LH
& Sysmex SP-10
nuclear remnants of lymphocytes and a lot found in CLL
Smudge cells
Purpose of blood smear staining
for evaluation of cellular morphology
fixative
methanol
stain
wright or wright giemsa
buffer
0.05 M Sodium Phosphate (pH 6.4)
Romanowsky stain contains
methylene blue + eosin B or eosin Y
most commonly used type of stain in the hematology laboratory
Romanowsky stain
examples of Romanowsky-based stain
Wright stain, Giemsa stain, and May-Grunwald stain
automated staingin
Midas III,
HEMA-TEK
Coulter LH
Sysmex SP-10
Macroscopic appearance of well-stained smear
pink-to-purple
microscopic appearance of well stained smear
RBCs: orange to salmon pink
WBC nuclei: purple to blue
Neutrophil cytoplasm: pink to tan
Eosinophil granules: bright-orange
RBCs: gray (or blue)
WBCs: too dark
Eosinophil granules: gray
- buffer is too basic
- inadequate rinsing
- heparinized blood
RBCs: too pale or are red
WBCs: barely visible
- stain/buffer is too acidic
- under buffering
- over rinsing
(presence of more than four times the
number of WBCs per field at the lateral edges
snowplow
snowplow is detected in what obective
10x obective
