Demonstration Dtotal White Blood Cell Count

A hemocytometer is used to make a total white blood cell count in much the same way that it was used to count red blood cells. However, in the case of white cell counting, a diluting fluid is used that destroys red blood cells. Also, in making the white cell count, all of the cells in the four large squares marked W in figure 39.4 are included. The total count is multiplied by fifty to calculate the total number of white blood cells in a cubic millimeter of the blood sample.

1. To perform a total white blood cell count, follow these steps:

a. Clean the hemocytometer as before.

b. Lance the tip of a finger, as before, to obtain a drop of blood.

c. Repeat steps 1c-1g of the procedure for counting red blood cells, but use a Unopette system for counting white blood cells.

d. After mixing the blood with the diluting fluid in the reservoir, discard the first four drops of the mixture and charge the hemocytometer with diluted blood as before.

e. Use low-power magnification to locate the areas of the grid corresponding to those marked with W in figure 39.4.

f. Count all of the cells in the four large squares (remember that the red blood cells were destroyed by the white blood cell diluting fluid), following the same counting rules as before.

g. Multiply the total by fifty and record the result in Part A of the laboratory report.

h. Discard or clean the materials as directed by the laboratory instructor.

2. Complete Part E of the laboratory report.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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  • michelina
    What magnification is used to do a total white blood cell count with a hemocytometer?
    5 years ago

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