This document provides instructions for counting white blood cells (WBCs) using a hemocytometer. It states that the four corner squares of the hemocytometer grid should be used to count WBCs, which should be distributed evenly among the squares with no more than a 10 cell variation. The document outlines that cells touching the outside lines should be counted according to whether they touch the left/right and upper/lower lines. Consistency is important, and the total counts from each side should agree within 10% or the procedure must be repeated.