Peripheral Blood Smear (PBS) Flashcards
• Purpose:
• Specimen:
To examine blood cells (rbc, wbc, and platelets) under the microscope to diagnose a disease.
Whole blood
can be used but not preferred; EDTA blood reveals better morphology
SODIUM CITRATE
SODIUM CITRATE tubes are used when ther eis presence of
platelet satellitosis
_________ when anticoagulated with EDTA.
• The platelets surround or adhere to neutrophils, which potentially causes_______ when counting is done by automated methods
• In addition, spuriously low platelet counts and _______can result from EDTA- induced platelet clumping.
platelet satellitosis
pseudothrombocytopenia
falsely increased WBC counts (pseudoleukocytosis)
______\ EDTAis often preferred to the powdered form because it mixes more easily with blood.
High-quality blood films can be made from the blood in the EDTA tube, provided that they are made within 2 to 3 hours of drawing the specimen!
Liquid tripotassium EDTA
K3
occurs when platelet agglutinates are similar in size to WBCs and automated analyzers cannot distinguish the two.
Pseudoleukocytosis
Preparation of Smear (3)
Wedge
Cover Glass
Automated
Manual wedge technique
2 slides used
Film slide
Spreader slide
• EASIEST TO MASTER
• Convenient and commonly used
MANUAL WEDGE TECHNIQUE
MANUAL WEDGE TECHNIQUE
2 types
Push
Pull
Tips to make a Good blood film
SPA
• The_______: too large a drop creates a long or thick film, and too small a drop often makes a short or thin blood film.
• Maintaining an ________on the slide is essential.
• It is also crucial to ______all the way to the end of the film
• If two or three films are made, the best one is chosen for staining, and the others are disposed of properly.
Some laboratories require two good films and save one unstained in case another slide is required.
SIZE OF THE DROP of blood is important
even, gentle pressure
keep the same angle
Manual wedge technique
PROCEDURE
1. A drop of blood (_____in diameter) is placed at one end of the smear slide.
a.______ (used in malarial smear because it needs thick and thin smear)
b._____ (Much better)
- The spreader slide is placed at about a ______ angle against the smear slide (Figure A)
- The______ is drawn back into the drop of blood, and the blood is allowed to spread across the width of the slide (Figure B)
- The spreader is then quickly and smoothly pushed forward at the end of the smear slide to create a wedge film (Figure C).
5.______
2-3 mm
Grounded Slide
Frosted slide
30-45°
spreader
Margin-free
Manual wedge technique
PROCEDURE
1. A drop of blood (_____in diameter) is placed at one end of the smear slide.
a.______ (used in malarial smear because it needs thick and thin smear)
b._____ (Much better)
- The spreader slide is placed at about a ______ angle against the smear slide (Figure A)
- The______ is drawn back into the drop of blood, and the blood is allowed to spread across the width of the slide (Figure B)
- The spreader is then quickly and smoothly pushed forward at the end of the smear slide to create a wedge film (Figure C).
5.______
2-3 mm
Grounded Slide
Frosted slide
30-45°
spreader
Margin-free
Dimension if glass slide
3 x 1 inches
Space before smear
Smear size
Space after smear
0.5 in
2/3 or 3/4 of the slide
0.25 in or 1cm
Features of a well-made PBS
- The film is_______ the length of the slide.
- The film is_____ shaped, very _____at the feather edge. NOT____ shaped; this provides the widest area for examination.
- The lateral edges of the film are visible.
- The film is smooth without (3).
- When the slide is held up to the light, the thin portion (feather edge) of the film has a “____” appearance.
- The_____ is picked up and spread.
two thirds to three fourths
finger; slightly rounded ; bullet
irregularities, holes, or streaks
rainbow
whole drop of blood (bawala ng naay tutoy)
Unacceptable Peripheral Blood Smear
A. Chipped or rough edge on spreader slide
B. Hesitation in forward motion of spreader slide
C. Spreader slide pushed too quickly
D. Drop of blood too small
E. Drop of blood not allowed to spread across the width of the slide
F. Dirt or grease on the slide; may also be due to elevated lipids in the blood specimen
G. Uneven pressure on the spreader slide
H. Time delay; drop of blood began to dry
FACTORS THAT DETERMINE THE THICKNESS OF SMEAR (PASS)
Pressure of spreader on slide
Angle between slide and spreader
Size of blood drop
Speed of spreader
Thick Smears ASS
Too high angle
Too large drop of blood
Too fast