2. Counting the WBC
• Keep the counting chamber horizontal
• Place the hemocytometer on the stage of
microscope
• Using the low power (10x) objective,
make ccertain the microscope light is
adjusted correctly.
• In proper focus, the white blood cells
should look small dark dots
3. • Scan the four large corner squares
marked "W".
• For accurate white counts , there
should be an even distribution of cells
in all four large squares , with no
more than a ten-cell variation
between the four cells.
• Beggining w/ the upper left square
count all th e WBC per large squares
with a pattern of UP->UR->LR->LL
then add all the WBC per squares to
get the total number of cells.
Four corner
squares are
meant for WBC
counting.
Total = 64 small
squares
4. if using a UNOPETTE
method?
• ALL NINE LARGE
SQUARES OF THE
HEMOCYTOMETER GRID
ARE USED TO COUNT
WBCs
5. Counting per square
• in counting the cells that touch the outside
lines of the outside of the square, count only
those that touch the left (or right) and upper
(or lower) outside lines.
• in counting the chambers with double lines,
disregarding those touch the right (of left)
and lower (or upper) outside margin.
• If the chamber has 3 lines , count those cells
that touch the middle line of the three
outside lines on two sides and
disregard those touching the
corresponding
lines on the other two
sides.
• Consistency is a must
6. • Count the cells on the opposite side of
the counting chamber and record the
number of cells counted in these four
large squares.
• The total number of cells counted on
each side of the counting chamber
should agree within 10% of each
other . if the count should not agree,
the procedure must be repeated.
