Laboratory Activity 9: DIFFERENTIAL WHITE CELL COUNT and (WHITE BLOOD CELL COUNT ESTIMATION) Flashcards
The (?) does not distinguish cell types.
total WBC count
Since there are several types of WBCs, the (?) is done to classify the types of leukocytes present in the blood.
WBC differential
It consists of enumeration of the relative proportion of the various types of WBCs as seen on stained blood smears.
WBC differential
This study often provides information in determining the severity and extent of an infection.
WBC differential
The (?) may also be estimated from a stained blood smear for the purpose of checking the validity of an automated WBC count result.
number of white blood cells
This is an inexpensive and speedy alternative.
WBC differential
The WBCs are estimated on the smear using (?) in an area where the red cells are not or are just slightly overlapping
high power lens
- Focus the stained smear under (?) to scan areas where cells are just lying side by side. Avoid thick portion since cells are crowded and overlapped.
LPO
- Examine and identify the types of white cells under
oil immersion field.
- Differentiate the various types of white cells making particular attention to:
Relative size
Nucleus
Cytoplasm
Nucleus
indentation or presence of filament and number of lobulation/segmentation
staining characteristics
Cytoplasm
outline
granules and their staining characteristics
- Using the (?), count the cells in consecutive fields as the blood smear is moved from side to side beginning from the thin area of the smear.
cross-section method
- With normal WBC count, at least (?) should be classified and recorded.
100 white cells
- Report results of the (?) classified as a percentage. These results are considered relative cell counts.
100 cells
- Absolute count may be computed as follows:
Absolute count (WBC type) = relative count x WBC count
WBC Estimation:
1. Focus the stained blood smear under (?).
2. Count the number of WBCs seen in (?) using a tally counter, in the area of the
smear where the red cells are only slightly overlapping.
3. Include fields with no WBCs in the estimate and count (?).
4. Get the average count from all 10 fields and multiply by (?) to get the total white blood cells estimate per
cubic millimetre.
high power objective
10 random high power fields
smudge or broken cells
2000
WBC Estimate =
Notes: The WBC estimate should agree (?) with the automated or manual WBC count/ul; The WBC count is reported if estimate agrees; The WBC estimate is never reported.
+ 20%
