After discarding the first 3 drops, charge
the counting chamber of the hemacytom-
eter by gently squeezing the reservoir.
Using the high power objective, count the
red blood cells in the red blood cell count-
Calculations: Multiply the number of cells
counted by 10,000 to obtain the red cell
Example: The number of cell in the 5
counting squares was 423.
scale, and on the opposite side is the
gram scale. The percentage scale reads
from 0 to 170. The gram scale reads
from 0 to 24.
. Pipette, marked at the 20 mm3 level
. Stirring rod
The cell count = 423 x 10,000
. Color comparator, with a window in
the side. On the right and left sides of
this opening is the color standard for
comparison. The center has an open
slot to hold the graduated tube.
Of the many methods of hemoglobin estima-
tion, the most accurate is reading of hemoglobin
as oxyhemoglobin in the photometer, after dilu-
tion of the blood with a weak alkali. The Haden-
Hausse, Sahli-Hellige, and Newcomer tests, based
on acid hematin formed by the action of hydro-
chloric acid on hemoglobin, are sufficiently ac-
curate for routine examination, provided they are
properly done. Since relatively few ships and sta-
tions are equipped with a photometer, we will
discuss the Sahli-Hellige method.
Materials Required for Sahli-Hellige Test
. Distilled water
Small bottle of dilute (approx. 0.1N)
hydrochloric acid. Prepare this solution
by adding 1 ml of concentrated HCl to
99 ml of distilled water. POUR ACID
INTO WATER. Replenish this peri-
odicallyit must be of proper strength.
Graduated tube, with a scale on two
With a medicine dropper, place 5 drops of
the 0.lN HCl in the bottom of the
graduated tube. Place the tube in the color
Using well-mixed venous blood or fingertip
blood, fill the pipette to the 20 mm3 mark.
Wipe blood from the outside of the pipette.
Transfer blood to the Sahli tube. Note the
Aspirate distilled water into the pipette two
or three times and transfer these washings
to the tube.
Shake until the blood is well mixed and the
tube is a uniform color.
Add distilled water, drop by drop, each
time mixing the solution with the stirring
rod. Keep adding water and mixing until
the color of the solution matches the stan-
dards on either side. Remove the stirring
rod from the tube each time before com-
paring. Natural light makes more accurate
Five minutes after time noted, read the
result from the scale on the tube by noting
the graduation mark at the lower edge of
the meniscus. Read and report both scales.
Reporting. Findings are reported both in
grams per 100 ml of whole blood and in percent-
sides. On one side is the percentage
ages of normal values. There are a number of