(b) Solution B: Dissolve 9.08 grams potassium acid phosphate
(KH2PO4) (monobasic), anhydrous, in a 1-liter volumetric flask containing about 750 ml
of distilled water. Dilute to the mark with distilled water.
(c) Mix 27 ml of the Na2HPO4 solution (Solution A) with 73 ml of the
KH2PO4 solution (Solution B). quarts to 1 liter. Final pH should be 6.4.
Wright's stain solution.
(a) Add 9.0 grams of Wright's powder stain, 1.0 gram of Giemsa
powder stain, and 90 ml of glycerin to a mortar of suitable size. Triturate this mixture
thoroughly for 15-30 minutes.
(b) Transfer the mixture to a large open-mouth jar (a kitchen spoon is
ideal for this purpose). Cover the jar and incubate the glycerin stain mixture overnight
(c) Transfer the glycerin/stain mixture to a large brown bottle and add
2,910 ml of acetone-free methanol.
(d) Age the Wright's stain solution approximately 2 weeks in the dark.
Mix daily to assure that the Wright's stain powder is completely dissolved.
Commercially available Wright's stain is available through the Federal supply
a. Make a finger puncture or venipuncture in the usual manner.
b. Touch a drop of blood to a clean glass slide at a point midway between the
sides of the slide and a short distance from one end. If a venipuncture is made, use a
capillary tube to transfer a drop of blood from the tube to the slide. If a finger puncture
is made, dispense the drop of blood from the puncture site after discarding the first
The drop of blood should be no larger than 1/8 to 3/16 inch in diameter (see
figure 3-5, side method for preparation of blood films, a through c.
c. Lay the specimen slide on a flat surface and hold it securely. Place a smooth,
clean edge of the spreader slide on the specimen slide at an angle of about 300 from the
horizontal (see figure 3-5a).