Laboratory Activity 9: DIFFERENTIAL WHITE CELL COUNT and (WHITE BLOOD CELL COUNT ESTIMATION)

Question 1

The (?) does not distinguish cell types.

Answer 1

total WBC count

Question 2

Since there are several types of WBCs, the (?) is done to classify the types of leukocytes present in the blood.

Answer 2

WBC differential

Question 3

It consists of enumeration of the relative proportion of the various types of WBCs as seen on stained blood smears.

Answer 3

WBC differential

Question 4

This study often provides information in determining the severity and extent of an infection.

Answer 4

WBC differential

Question 5

The (?) may also be estimated from a stained blood smear for the purpose of checking the validity of an automated WBC count result.

Answer 5

number of white blood cells

Question 6

This is an inexpensive and speedy alternative.

Answer 6

WBC differential

Question 7

The WBC􏰁s are estimated on the smear using (?) in an area where the red cells are not or are just slightly overlapping

Answer 7

high power lens

Question 8

1. 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.

Answer 8

LPO

Question 9

2. Examine and identify the types of white cells under

Answer 9

oil immersion field.

Question 10

3. Differentiate the various types of white cells making particular attention to:

Answer 10

Relative size

Nucleus

Cytoplasm

Question 11

Nucleus

Answer 11

indentation or presence of filament and number of lobulation/segmentation

staining characteristics

Question 12

Cytoplasm

Answer 12

outline
granules and their staining characteristics

Question 13

4. 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.

Answer 13

cross-section method

Question 14

5. With normal WBC count, at least (?) should be classified and recorded.

Answer 14

100 white cells

Question 15

6. Report results of the (?) classified as a percentage. These results are considered relative cell counts.

Answer 15

100 cells

Question 16

7. Absolute count may be computed as follows:

Answer 16

Absolute count (WBC type) = relative count x WBC count

Question 17

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.

Answer 17

high power objective

10 random high power fields

smudge or broken cells

2000

Question 18

WBC Estimate =

Question 19

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.

Answer 19

+ 20%