CLS 1531 LABORATORY FOR URINE AND
BODY FLUID ANALYSIS
LABORATORY EXERCISE VI
BODY FLUID: CEREBROSPINAL FLUID
(CSF Evaluation and cell count)
INTRODUCTION
Cerebral spinal fluid (CSF) is a modified ultra filtrate of blood and is
affected by pathological changes within the Central Nervous System. These
changes can be either chemical or cellular. CSF is obtained by the physician
through a lumbar puncture. This laboratory activity will provide the student the
opportunity to:
1. Develop skills using the Neubauer Counting chamber
2. Recognize color, clarity, and viscosity of CSF
3. Perform a cell count on clear and/or cloudy CSF
4 Calculate a true WBC count from a traumatic tap
5. Correctly handle CSF specimens
6. Understand and explain safety concepts
EQUIPMENT AND MATERIALS
1. Microscope
5. Diluting fluid
2. Hemocytometer (Neubauer)
6. Artificial CSF Specimens
3. Tally counter
7. Capillary pipets
4. Pipetting device
PROCEDURE
1. Use the techniques for counting as described in laboratory
lesson V.
2. Select an artificial CSF specimen. Note the color and
appearance, then
mix well.
A. If the
specimen is clear, then it can be assumed that if cells are
present, there can be no more than 360 cells (WBC and/or RBC) per
cu.mm. Haziness due to the presence of cells in CSF occurs when the
count is greater than 360 per cu.mm.
B. If the
specimen is clear, then fill the counting chamber with undiluted
fluid, using a capillary pipet.
C. If the
specimen is hazy, then use a 1:20 dilution.
D. If the
specimen is strongly hazy to cloudy, a 1:200 dilution may be
preferred.
3. Count cells by one or both of the following methods:
UNDILUTED FLUID
1. Count all nine 1 mm × 1 mm ruled squares on side A
and side B and average.
A. multiply by the volume
correction factor and report the corrected count.
2. Alternate Method:
A. Count five 1 mm
× 1 mm ruled squares on side A, then repeat for side
B (see Figure 2, lesson V, squares labeled 1 and 2).
B. Total both sides
and report results. This is a total of 10 squares and
represent 1.0 μL.
Note:
Normal spinal fluid will contain less than 11 WBC and 3 RBC's
in each μL.
DILUTED FLUID.
1. Select a new sample and make a 1:20 dilution using one of
the techniques
described in laboratory exercise V.
2. Perform calculations as instructed in the previous
laboratory exercise V.
3. Record your results on the report form on the work sheet
section of this
Laboratory activity.
4. If RBC are present, indicate if they are crenated or not.
5. Include the following information on the report form.
A. appearance
(clear, hazy, cloudy)
B. color
(colorless, Xanthochromic or the color actually visualized)
C. If it is obvious
that blood is present then indicate if there is slight,
moderate or grossly bloody.
D. If the specimen
is hemolyzed, then report this fact.
7. Optional. Perform only if required by the lab instructor.
A. If the WBC count
is more than 20 in your specimen sample, then
prepare a differential count of the white cells.
B. Centrifuge the
specimen
C. Pour off the
supernatant and save
D. Resuspend the
"sediment" in the residual fluid
E. Transfer a drop
of the resuspended sediment to a glass slide and make
a smear. The instructor will demonstrate this technique if you are not
familiar with the procedure and this is required as part of the lab
activity.
F. Fix in methanol
G. Stain with
Wright's stain or other suitable stain
H. Evaluate 100 WBC
and report as percent.
I. designate the
cells into two categories: multinucleated and
mononucleated form.
There is not a Laboratory Exercise
Worksheet for this CSF Lab. Obtain a sheet of typewriter or
photocopy paper and fill in as follows:
01. Your name in the upper left corner
02. Under your name write in the name of the lab.
03. In the right upper corner, write in the date of the lab.
04. Write in your lab data on the page.
The following Problem Set is due the next laboratory
period after finishing this laboratory activity. You are expected to
complete this by your self. If you are found copying this work from
another's worksheet, both assignments will be given the grade of zero.
The answers are in your textbook and classroom notes.
Write legibly.
Problem Set I: Cerebrospinal Fluid
NAME: ___________________________________________ Date: _____________
01. From what specific area of the spine does the physician
collect the spinal fluid?
02. Why is the CSF chloride test a useful test procedure for
the physician to order or is it?
03. A spinal fluid was found to contain 4450 RBC/μL and 27
WBC/μL. The peripheral count values for the RBC = 4.37 × 1012/L and the WBC =
9.4 × 109/L. What is the corrected WBC count. Include the formula as part of
your answer. Use the back of your worksheet if you need extra space.
04. What is the clinical value of a RBC count in a spinal
fluid evaluation?
05. The spinal fluid of a healthy neonate is reported to be
xanthochromic. Should the physician be concerned about this observation? Circle
your response. Yes. No.
Explain why this is of concern or of no concern.
06. List four microorganisms that causes bacterial
meningitis.
A.
B.
C.
D.
07. If a CSF gram stain is reported as being negative, does this mean that the
physician can rule out a bacterial infection? Circle your response. Yes. No.
Explain why the physician can or cannot rule out an infection.
08. Which leukocytes are usually observed in the CSF of a healthy adult?
09. Which leukocytes would most likely be observed in the CSF of a patient
diagnosed with bacterial meningitis?
10. Which of the following tests would you recommend to evaluate the
effectiveness of antibiotic therapy? Circle your response.
lactate glucose
chloride protein electrophoresis
lactate dehydrogenase
11. List the normal values for the following:
A. WBC (blood): _______________________
B. WBC (CSF): _______________________
C. Neutrophils (per 100 WBC in CSF): _______________________
D. CSF pressure in mm H20:
_______________________
E. Glucose (blood): _______________________
F. Glucose (CSF): _______________________
G. Total Protein (blood): _______________________
H. Total Protein (CSF):
________________________
When you have completed this problem set, be sure that your name is on this
page, If there are two
pages, staple in the upper left corner before turning in and initial the
second page.
Revised for spring 2006
