Page 603 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

CHAPTER 29 ■ Body Fluid Analysis 587

( able 29.4) and a delay in the examination o a speci- protein or gel ormation on standing due to an increased

men (which can cause a alse-positive result) can produce brinogen content.

xanthochromia.
Microscopic Exam ination: Cellular Enum eration

Viscosity Electronic cell counters are usually used to count cells in CSF.

Normal CSF has the viscosity o water. Clotting in CSF can Occasionally, total leukocyte cell counts on body f uids are

be caused by a variety o conditions, including increased per ormed manually.

SPINAL FLUID: TOTAL LEUKOCYTE COUNT PROCEDURE

PRINCIPLE

o enumerate the number o WBCs to assist in the devel-

opment o a di erential diagnosis (e.g., bacterial meningitis,

viral meningitis, ruptured brain abscess). W W

REAGENTS, SUPPLIES, AND EQUIPMENT

1. 10% acetic acid: Prepare by lling a 100-mL volumetric R R
f ask about hal ull with distilled water. Using a sa ety

bulb, pipette 10 mL o glacial acetic acid into the f ask.
Add distilled water to the calibration mark and mix. R

2. Wright-Giemsa or Wright’s stain or 1% methylene blue in
methyl alcohol: Prepare by weighing 1 g o methylene blue R R

and trans erring it to a 100-mL volumetric f ask. Dilute to
the calibration mark with methyl alcohol. Mix.

3. Small (12- × 75-mm) test tubes, Pasteur pipettes, rubber
bulb, and microscope slides W W

4. Neubauer’s hemacytometer
5. Centri uge, microscope, and immersion oil

6. Disin ectant solution
7. Disposable gloves and sa ety goggles FIGURE 29.2 Neubauer’s counting chamber. (R, red cell area;

W, white cell area.)

PROCEDURE
the outer lines or the opposite adjacent lines should not
1. Mix the spinal f uid by inversion. With a Pasteur pipette, be counted (see Fig. 29.3).

trans er nine drops o spinal f uid to a small test tube. Add T e number o cells counted in all nine squares should

one drop o 10% acetic acid. Mix by gently tapping the not di er by more than ve cells. Average the count rom

tube. both sides.

2. Allow this mixture to stand or 5 minutes. Mix again.

3. o each side o the chamber o a clean hemacytometer

with a coverslip, load a small amount o the diluted spinal

f uid. Allow the counting chamber to sit covered, with a

moistened lter paper in hal o a Petri plate, or a ew

minutes to allow the cells to settle and the erythrocytes to

completely lyse.

4. Place the hemacytometer under the 10× microscopic

objective (low power). Erythrocytes should either be Counted

absent or appear as ghost cells. he nucleus o poly- Not counted

morphonuclear segmented neutrophils (PMNs) will

be bright, whereas the lymphocyte nucleus will be

round.

5. T e leukocytes in all nine squares o each side o the

chamber should be counted (see Fig. 29.2). Remove the

“R” rom the inner ve squares. I cells touch the inner

or middle lines o two adjacent lines, or example, upper

and le -hand side, they can be counted. Cells touching FIGURE 29.3 RBC counting square.