[2S] UNIT 8 RBC Counting Flashcards
The number of erythrocytes contained in 1 liter of blood is called?
Erythrocyte Number Concentration
T/F: The results of an RBC count can be used to help diagnose blood-related conditions, such as anemia, polycythemia and others
T
What tube should be used when collecting blood for RBC count?
EDTA - Anticoagulated blood
In traditional units, Erythrocyte Number Concentration is expressed as the?
number of cells per cubic millimeter
In traditional units, Erythrocyte Number Concentration is expressed as the number of cells per cubic millimeter and is called the?
Erythrocyte or Red Blood Cell Count
T/F: The RBC pipette has a wider bore
F; smaller
Aspirate up to?
0.5-1.0
Tube that retains cell morphology
EDTA/Lavender Top
5 tertiary squares (R squares) of the central secondary square
Hemacytometer
CHARACTERISTICS OF A GOOD RBC DILUTING FLUID
T/F: Must be a hypertonic solution
F; isotonic (balanced solute & solvent)
CHARACTERISTICS OF A GOOD RBC DILUTING FLUID
T/F: Must have a high specific gravity
T
CHARACTERISTICS OF A GOOD RBC DILUTING FLUID
T/F: Must be easy to prepare and cheap
T
CHARACTERISTICS OF A GOOD RBC DILUTING FLUID
T/F: Must be a good preservative
T
CHARACTERISTICS OF A GOOD RBC DILUTING FLUID
T/F: Must not have buffer action
F; must have buffer action
CHARACTERISTICS OF A GOOD RBC DILUTING FLUID
T/F: Must not initiate the growth of molds
T
COMPOSITION
- 40% solution of formaldehyde: 10.0 mL
- 3% W/V trisodium citrate: 990.0 mL
Dacie’s / Formol Citrate
Best RBC diluting fluid since cell shape is not altered
Dacie’s / Formol Citrate
Can be stored for long periods of time without growing fungi or molds
Dacie’s / Formol Citrate
COMPOSITION
○ Mercuric chloride, cp: 0.50 gm
○ Sodium chloride, cp: 1.00 gm
○ Sodium sulfate, cp crystalline: 5.00 gm
○ or anhydrous: 2.65 gm
○ Distilled water: 200.00 m
Hayem’s (Me SCared ASs Duck)
Allows growth of yeast
Hayem’s
Produces clumping of cells
Hayem’s
Can stand for long period
Hayem’s
No corrosive effect
Hayem’s
Prevents Rouleaux formation
Gower’s
COMPOSITION
○ Glacial acetic acid: 16.65 gm
○ Sodium sulfate, cp crystalline: 6.25 gm
○ Distilled water: 100.00 ml
Gower’s
GOWER’S
Stack of coins
Rouleaux formation
Precipitates protein in hemoglobinemia and hyperglobulinemia
Gower’s
GOWER’S
Usually observed in infection (multiple myeloma, connective tissue disorders)
Rouleaux formation
COMPOSITION
○ Methyl violet: 0.025 gm
○ Sodium Chloride: 1.00 gm
○ Sodium sulfate: 8.00 gm
○ Glycerine: 30.00 gm
○ Distilled water: 200.00 ml
Toisson’s (MeV SCared SiS GanDa)
Stains WBC to aid in the differentiation of WBC from RBCs.
Toisson’s
Beginners are recommended to use this because WBC are easily identified.
Toisson’s
Supports growth of fungi
Toisson’s
Has high specific gravity
Toisson’s
Can stain WBC
Toisson’s
The use of distilling fluid should also be filtered from time to time to prevent the growth of fungi
Toisson’s
COMPOSITION
○ Sodium chloride: 1.00 gm
○ Sodium merthiolate, 1:1000 solution: 2.00 ml
○ Sodium sulfate, crystalline: 5.00 gm
○ Glycerine: 20.00 gm
○ Distilled water: 200.00 ml
Bethell’s (SCared So Much SiS GanDa)
Other name for normal saline solution
Physiologic Saline Solution
Used in emergency cases and excessive rouleaux formation and auto agglutinated cells
Normal Saline Solution / Physiologic Saline Solution
It is stable and serves as a preservative
Normal Saline Solution / Physiologic Saline Solution
COMPOSITION
○ Sodium Citrate
○ Distilled Water
3.8% Sodium Citrate
COMPOSITION
○ Sodium chloride
○ Distilled water
Normal Saline Solution / Physiologic Saline Solution
PROCEDURE
T/F: The first step is to mix your EDTA tube or blood sample before aspirating.
T
PROCEDURE
T/F: After aspirating, do not wipe off the excess blood at the tip of the pipette
F; Wipe off excess blood at the tip of the pipette using a clean piece of tissue
PROCEDURE
T/F: Draw the diluting fluid up to the 101 mark
T
PROCEDURE
T/F: Mix the contents of the pipette while in vertical position
F; horizontal
PROCEDURE
T/F: When mixing the contents of the pipette, secure the pipette by using your thumb and middle finger to make sure the contents are in homogenous solution by mixing it.
T
Dilution factors
100 or 200
PROCEDURE
T/F: Place the thick coverslip. Before charging we must remember to place the thick coverslip and to make sure that the coverslip and counting chamber are free from dirt, thumb marks, tissue strands or any contamination.
T
PROCEDURE
T/F: Before charging, do not reshake the pipette.
F; Before charging, make sure to reshake the pipette.
PROCEDURE
T/F: We discard the first 5-6 drops because the mixture or solution present in the capillary stem, which is the first few drops of the diluted blood, are cell free.
T
CHARGE
Angle of the pipette while charging
30-35 degrees
CHARGE
Fill the counting chamber by capillary action or the?
Hanging Drop Technique
CHARGE
Let the counting chamber stand for how many minutes
5-10 mins
SOURCES OF ERROR IN RBC COUNTING
Did not discard the first few drops from the pipette
Operator’s Technical Errors
SOURCES OF ERROR IN RBC COUNTING
Incorrect aspiration/dilution
Operator’s Technical Errors
3 Sources of Error in RBC Counting (Manual)
ERRORS DUE TO:
- Materials / Equipment
- Nature of Sample
- Operator’s Technical Errors
SOURCES OF ERROR IN RBC COUNTING
Overcharging / Undercharginh
Operator’s Technical Errors
SOURCES OF ERROR IN RBC COUNTING
Presence of air bubbles upon charging
Operator’s Technical Errors
SOURCES OF ERROR IN RBC COUNTING
Incorrect counting (did not exclude bottom/right)
Operator’s Technical Errors
SOURCES OF ERROR IN RBC COUNTING
After charging, immediately stage the counting chamber in the microscope and start the count
Operator’s Technical Errors
SOURCES OF ERROR IN RBC COUNTING
Presence of dirt or debris in coverslip/counting chamber
Errors Due To Materials / Equipment
SOURCES OF ERROR IN RBC COUNTING
Use of old or unfiltered diluting fluid (may lead to growth of fungi/presence of yeast cells)
Errors Due To Materials / Equipment
SOURCES OF ERROR IN RBC COUNTING
RBC pipette used was not clean and dry (red bead should be moving freely)
Errors Due To Materials / Equipment
2 Variations in Technique
RBC is markedly increased & decreased
2 VARIATIONS IN TECHNIQUE
Increase the volume of aspirated blood. Compute for dilution accordingly
RBC is markedly decreased
2 VARIATIONS IN TECHNIQUE
Decrease the volume of aspirated blood. Compute for dilution accordingly
RBC is markedly increased
2 VARIATIONS IN TECHNIQUE
Use standard blood volume but increase the number of tertiary squares to count. Compute for the revised area factor accordingly
RBC is markedly decreased
CORRELATION
5 Pathologic Variation
PAHDS
- Polycythemia
- Anemia/Oligocythemia
- Hemorrhage
- Drugs
- Secondary to other disorders/disease
CORRELATION: PHYSIOLOGIC VARIATION
T/F: Men have higher counts than women
T
CORRELATION: PHYSIOLOGIC VARIATION
T/F: Adults have higher counts than newborns
F; Newborns have higher counts than adults
CORRELATION: PHYSIOLOGIC VARIATION
T/F: Dehydration and strenuous activities may result to decreased counts
F; increased
● Principle: Solution Turbidity
● The more turbid the solution, the more cells are present in the solution
Photoelectric Method
CORRELATION: PHYSIOLOGIC VARIATION
T/F: Decreased counts in individuals living at higher altitudes
F; increased
3 other methods for RBC counting
Unopette System
Photolelectric Method
Automated Analyzers
Principle: Electronic Impedance/ Flow Cytometer/ Coulter principle
Automated Analyzers
Reference range for males
4.5-6.0 M/cumm
Reference range for females
4.0-5.5 M/cumm
Reference range for late pregnancy
3.0-5.0 M/cumm
Reference range at birth
7.0 M/cumm
Conversion of CU to SI
Conventional x 0.000001
S.I. unit for RBC count
x10^12/L