Download - Physiology Lab 2, Manual RBCs Count
manual RBCs count
Introduction
Erythrocyte (RBCs) are biconcave in appearance Have no nucleus
The interior of the cell contain red pigment called Hemoglobin which is responsible for red color of blood.
Life span 120 days
Introduction
The function of erythrocytes to combine with O2 & to lesser extent CO2 & transport them through blood vessels.
Introduction
Normal range in healthy adult male has about 4.5-6 million RBCs/mm³
healthy adult female has about 4-5.5 million RBCs/mm³
Principle of the test
In this experiment you are going to determine the # of RBCs in mm³, and because this # is very large, dilute a sample with an Isotonic Solution (Hayem’s solution), then multiply the counted # by correction factor.
Material
1. Blood sample (EDTA anticoagulated blood or capillary blood)
2. RBCs diluting pipette3. Diluting solution (Hayemes solution)4. Hemocytometer5. microscope
RBCs diluting pipette
The Hemacytometer
]0.25mm
]0.20mm
Methodology
With a safety bulb draw blood up to 0.5 marks on RBCs pipette and complete to 101 with RBCs diluting solution.
Mix for 2-3 minute.
Charge hemacytometer
Discard the first 4-5 drops
Place tip of the pipette at the edge central platform
Then let the hemacytometer to stand on the bench for 3-5 minute.
Count and calculate:
Calculation
Number of RBCs/mm³=counted cells in 5 squares(80 small squares)
x diluting factor x volume correction factor.
Calculation
The dilution factor= total volume/sample volume = 101-1/0.5 =200 Volume correction factor= Desired volume/counted volume in 5 squares 1 mm³/ counted volume
Calculation
counted volume =The total volume of the 5 Medium
squares== Volume x number squares= (width x length x depth )x 5= (1/5mm x 1/5mm x 1/10 mm) x 5
=1/4000mm³
Calculation
Total # of small squares= 5 x 16=80 Then The total volume of the 5
Medium squares=1/4000 x 80=1/50 Volume correction factor=
1/(1/50)=50
Calculation
Example: If total # of RBCs in 5 medium
squares is 423 Then the # of RBCs in 1mm³= 423 x
200 x 50 = 4,230,000
Calculation
Number of RBCs/mm³= counted cells in 5 m square x diluting factor x volume correction factor.
Number of cells/mm³= n x200 x 50 = n x 1000
Significance of the test
The purpose of a RBCs count is to determine the # of ciculating RBCs per mm³ of blood
RBCs carry O2 to all tissues; thus a drastic reduction in the RBCs count will cause immediate reduction in the available O2.
Significance of the test
Anemia: a decrease in number of RBCs below normal range
Polycythemia: Increase in number of RBCs above normal range
Physiological Polycythemia: (up to 8 million cells/mm³) due to:
Age: at birth RBCs count is 8-10 million cells/mm³ High altitude
Significance of the test
Pathological Polycythemia: due to Primary Polycythemia: RBCs over 14
million cells/ mm³, occur in bone marrow malignancy.
Secondary Polycythemia: RBCs over 8 million cells/ mm³,due to:
Respiratory disease Heart disease Chronic carbon dioxide poisoning
Sources of error
1. Flooding of chamber with excess sample
2. Failing to count all the cells in the squares or conversely including artifacts in the count.