Lab Worksheet #5: Red Blood Cell Count Flashcards
Blood is diluted with a/an (hypotonic/isotonic/hypertonic) solution for the preservation of the blood corpuscles.
Isotonic
This is the number of red cells in 1 cu mm of blood.
Red cell count
What are the characteristics of a good RBC diluting fluid?
Must: Be an isotonic solution Have a high specific gravity Be easy to prepare Be cheap Be a good preservative Have a buffer action Not initiate the growth of molds
Blood should be aspirated up to the ___ mark of the RBC pipette.
0.5
By syringe aspiration, draw the diluting fluid up to the ___ mark with constant rotation of the pipette to ensure proper mixing of the blood and the diluting fluid.
101
When aspirating the diluting fluid into the pipette, explain why constant rotation of the pipette must be done.
To ensure proper mixing of the blood and the diluting fluid.
What is the dilution ratio between the blood and the diluting fluid in the pipette?
1:200 or 1/200 dilution
What must be done if the diluting fluid goes beyond the 101 mark or if there is presence of bubbles inside the bulb?
Discard the mixture and start from the beginning making use of a dry clean pipette.
This is also known as filling the counting chamber.
Charging
How many drops of the diluted blood from the pipette must be discarded before charging the counting chamber?
5-6
What is the angle of the pipette while charging?
30 - 35
Overcharging can be readily observed by the presence of _____.
Fluid on the moats of the counting chamber.
This can be readily observed by the presence of fluid on the moats of the counting chamber.
Overcharging
Undercharging is observed by the failure to _____.
Cover the entire ruled area of the counting chamber.
This is observed by the failure to cover the entire ruled area of the counting chamber.
Undercharging
Air bubbles seen on the counting chamber indicates the _____.
Presence of moisture or dirt
_____ seen on the counting chamber indicates the presence of moisture or dirt.
Air bubbles
When finished filling the counting chamber (charging), let the pipette stand for ___ - ___ minutes to allow the RBCs to settle.
5 - 10
Count theRBCs seen on the 5 tertiary squares designated as _____.
R squares
The 5 squares, R squares, have an area of _____.
1/5 sq. mm.
Count the RBCs on the first row of the smaller squares from (left to right/right to left).
Left to right
RBCs that touch any of the lines on the top and left borders, even if they are outside the tertiary square, are (included/not included) in the count.
Included
RBCs that touch any of the lines on the bottom and right borders, even if they are inside the tertiary square, are (included/not included) in the count.
Not included
Record the count on each of the 5 tertiary squares making sure that the cell difference between two squares is ___ or less.
20
(T/F) All counts must be done in triplicates.
F - duplicates
What is the general formula for the computation of the number of blood cells / cu mm of blood?
No. of cells/cumm
= (total no. of cells counted)/(area X depth X dilution)
= (total no. of cells counted)/(1/5 X 1/10 X 1/200)
= cells counted X 10,000
What is the normal RBC count value for males?
4.5 - 6.0 M/cumm
What is the normal RBC count value for females?
4.0 - 5.5 M/cumm
What is the normal RBC count value during late pregnancy?
3.0 - 5.0 M/cumm
What is the normal RBC count value at birth?
7.0 M/cumm
This refers to an increased RBC count reflecting in an increased RBC mass, a condition that leads to hyperviscosity.
Polycythemia
