CLINICAL LAB SCIENEC

CHAPTER 12: PROCEDURES FOR URINALYSIS AND BODY FLUIDS 317
Specimen Collection and Preparation
For urine specimens, a random or 24-hour specimen may be used, depending on the
clinical situation.
For CSF measurements, great care must be exercised in handling CSF samples.
CSF samples are difficult to collect and some are highly infectious. CSF should be
free from hemolysis for the protein performance. Centrifuge all specimens containing
RBCs or particulate matter.
Equipment and Supplies
1. Gloves, disposable paper towels and disinfectant or other cleaning solution
2. Report form for recording results
3. Fresh urine sample that has tested positive for protein by dipstick (see Procedure #1)
a. Other body fluids will be collected by a physician and should be appropriate
for testing.
b. CSF sample divided among 3 test tubes. The first tube should be centrifuged
to remove RBCs or particular matter and the supernatant is used in testing for
protein.
4. Serological pipettes for measuring reagents. A Burette pipette with graduated
markings similar to that of a serological pipette may be used.
5. Micropipetters and disposable tips
6. 13 × 100 mm test tubes (one for each control sample and one for each sample to
be tested) and test tube rack.
7. Trichloroacetic acid (TCA), sulfosalicylic acid (SSA), or Coomassie
blue dye
8. Standards appropriate for fluid being tested, i.e., in g/dL for serum
and in mg/dL for other body fluids
9. Prepared normal and abnormal control samples
10. Cuvettes for determining absorbance of each tube containing
reagent, standards, controls, and samples (patient or unknown
samples)
11. Spectrophotometer capable of reading turbidity or color, depending
on methodology chosen
12. Vortex mixer (optional) or “parafilm,” a waxy paraffin sheet from
which small areas can be cut to use on the various tubes
13. Electronic timing device or clock/watch with second hand
14. Sharp permanent marker
Procedure
1. Wash hands and don gloves.
2. Assemble necessary equipment and supplies.
3. Label the 13 × 100 mm test tubes as follows for proper identification
of blanks, standards, controls, and unknowns: label one tube “B”
for the blank specimen, one tube “S” for the standard sample, and
one or more tubes “C (number)” for the control samples (e.g., C-1
and C-2 to differentiate between normal and abnormal controls).
Critical Reminders
Units of Measurement
Protein in blood serum is measured
in grams per deciliter (g/dL), while
that of other body fluids is measured
in milligrams per deciliter (mg/dL).
Protein that is found in body fluids
outside the vascular system is derived
from protein in the blood that has
passed through barriers such as cell
membranes and has entered into
other body fluids. It is imperative that
the appropriate standard is used for
determining protein in blood or in
other body fluids. It is important to
remember that protein in body fluids
other than blood is never higher or as
high as that found in the serum from
the blood.
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.