CHAPTER 3.5 - DIFFERENTIAL COUNT Flashcards
Quantitative and qualitative study of the types of leukocytes
DIFFERENTIAL COUNT
Represents the percentage distribution of the different WBCs
DIFFERENTIAL COUNT
DIFFERENTIAL COUNT Includes:
o Quantitative & qualitative study of thrombocytes
oAge and morphologic abnormalities or RBCs
DIFFERENTIAL COUNT
4 General steps:
- Preparation of blood smear
- Staining of the smear
- Counting of the cells
- Reporting
Blood smears must be made within
2-3 hours
Advantages of EDTA blood smear
1. Can create
2. May be prepared at
3. Avoids
multiple slides
later time
platelet clumping
SOURCES OF SPECIMEN:
EDTA BLOOD
ANTICOAGULANT FREE BLOOD (CAPILLARY BLOOD)
Best for evaluating blood morphology
ANTICOAGULANT FREE BLOOD (CAPILLARY BLOOD)
ANTICOAGULANT FREE BLOOD (CAPILLARY BLOOD)
Advantages:
• Made at the patient’s side
• Artifacts are minimized
ANTICOAGULANT FREE BLOOD (CAPILLARY BLOOD)
• Disadvantages:
• Platelet clumping
• Few films can be made
METHODS OF BLOOD SMEAR PREPARATION
BM preparations; NOT for routine
Coverslip Method
PBS
Coverslip Method
ADV: superior leukocyte distribution
Coverslip Method
Coverslip - rotated 45° (16sided)
Coverslip Method
Never touch the coverslips with fingers
Coverslip Method
Erlich’s
Coverslip Method
Beacom’s
Glass Slide-Coverslip Method
Wedge Slide/Push Smear
Two-Glass Slide Method
Uses 2 slides
Two-Glass Slide Method
Film slide
Two-Glass Slide Method
Two-Glass Slide Method Pusher Spreader slide
30-45 degree
Two-Glass Slide Method Considerations:
1. Drop of blood (?) in diameter
2. (?) of spreader (smooth & swift)
3. (?) of patient
2-3mm
Speed
Gct
Two-Glass Slide Method SPREADER SLIDE:
Must be (?) than the stationary slide
Spreading edge:
With
narrower
clean, smooth, polished & thin
beveled edge
Two-Glass Slide Method DISADVANTAGES:
Tendency of (?) at the slide edges & feathered ends (ADV: easier to find abnormal cells)
(?) of nucleated cells
Greater (?) to cells
larger cells to settle
Poor distribution
trauma
prepares dual smears simultaneously ata constant angle and speed.
Miniprep/Hemaprep
glass slides are placed on a platform inside the instrument (0.2 ml WB)
Hemaspinner
Instrument spins causing the slide to be covered with a monolayer of cells
Hemaspinner