Obtain an ocular grid etched with a square, and insert it into an ocular
of the microscope (or use a microscope previously set up by the instructor).
Calibrate the ocular grid in a manner similar to that outlined in Exercise 3,
and determine the area of each marked grid section. Draw the grid in the
space below and add all pertinent dimensions.
Place a prepared slide of a blood smear on the microscope and focus on
the slide using the 40X objective. Count the number of cells within the
4 margins of the grid area.
Count only cells that touch the top and left margins of the grid. Do not
count any cell that touches the right or bottom margin of the grid. Record
the number in the following box.
Select 4 additional random fields of view with approximately the same
density of cells and count the number of cells per grid. Record the numbers
in the space provided.
Average the results and, based on the known dimensions of your grid,
calculate the number of cells per mm2 for the blood smear.
Area of the grid (40X) ____________________