EXERCISE 1: Macroscopic Urinalysis
Urinalysis
1
MLAB 1211
Urinalysis PreTest
Macroscopic UA Lab

Instructor: Ragland
MLAB 1211
Pre-Test
Spring 2002
/
10 points
Name_______________________________
Date_____________________
INSTRUCTIONS: Each question is worth one point. Answer the questions on this
paper as appropriate: short answer, fill in the blank, true-false, and multiple choice.
1.
List at least two (2) changes that can occur in a urine specimen if it is allowed to sit
at room temperature and deteriorate.
1.
2.
2.
As stated in the lab guide, the normal values for urine specific gravity are
A.
1.000 - 1.015
B.
1.015 - 1.025
C.
1.020 - 1.035
D.
1.035 - 1.050
3.
The specific gravity of a liquid is defined as the density of the liquid when
compared to the density of at a specified temperature.
Match the following analytes with the test used to detect them..
4.
___protein
5.
___sugar
6.
___acetoacetic acid or acetone
7.
___bilirubin
A.
Clinitest
B.
Ictotest
C.
3 % sulfosalicylic acid
D.
Acetest
8.
Nitrites are formed in the bladder by the action of certain
on urinary nitrates.
9.
On what reaction is the test for urobilinogen based?
a. glucose oxidase
b. Ehrlich
C. Benedicts copper reduction
D. error of indicators
10. Other than intact RBCs, what two substances can be detected by the occult blood
pad?
&
EXERCISE 1: Macroscopic Urinalysis
Urinalysis
2
Macroscopic Urinalysis
Points
:
Points are awarded for Pre-test, Skills, including general lab
requirem ents, as we ll as su cce ssful and time ly completion of
Study Qu estions.
Objectives
:
Accordin g to the standard s se t by the instruc tor, the student w ill
be able to perform the following physical and rapid chemical
macrosco pic examinations within ± 20% accuracy.
1.
Color
2.
Transparency
3.
Specific gravity (by TS me ter and dipstick)
4.
Urine chem ical concentrations of protein, glucose, ketones,
bilirubin, blood, nitrite, urobilinogen, leukocyte esterase, and
pH using Multistix reagent strip method
5.
Prote in by su lfosalicy lic ac id
6.
Ketones by Acetest tablet method
7.
Bilirubin by Ictotest tablet method
8.
Reducing substances by Clinitest tablet method
Equipm ent &
Supplies:
1.
AO TS M eter
2.
Multistix reagent strips
3.
Urine contro ls
4.
Color charts for Multistix, Acetest, Ictotest, and Clinitest
5.
Pasteur or other transfer pipets @ 5 3/4" size
6.
3% sulfosalicy lic ac id
7.
Ace test tablets & p rodu ct insert
8.
Ictotest tablets , ab sorbent p ads & produ ct insert
9.
Clinitest tab lets, reaction tubes & prod uct inse rt
10.
Te st tubes, ra cks , marking pens, Kim -wipes, paper to we ls
11.
Distilled water and sodium chloride solution
References
:
Packag e inse rts M ultistix, Clinitest, Ace test, and Ictotest, Bayer /
Ames Company
McBride, L .J. (19 98). Textbook of Urinalysis and Body Fluids.
Lipp incott.
Graff, Laurine, A H andbook of Routine Urinalysis, pp. 2-65.
Stra singer, S . K. Urinalysis and Body Fluids, Chapter 4.
Principle
:
1.
Determining the physical properties of urine is done by
making simple but important empirical observations. Physical
properties can provide clues to subsequent findings and/or
dictate the need for additional tests not always performed on
each sample. In addition, the physical appearance of a urine
sam ple can often tell a gre at deal abo ut a patient's con dition.
A significant change in urinary color or clarity that deviates
from accepted normal classifications may indicate the
presence of a disease.
2.
It is important to work with a freshly collected sample or one
that has been properly preserved. A number of changes can
occu r in an a ging s am ple. Th ey are ou tlined in the Lecture
Gu ide a nd in your textbo ok u nder preservation . (HINT: Look EXERCISE 1: Macroscopic Urinalysis
Urinalysis
3
them up before lab tim e.)
3.
The first of the physical properties to be considered is color.
Th e color of u rine ofte n varie s w ith its concentration and is
most often reported as some shade of yellow (straw, light
yellow , yellow, dark y ellow, a nd a mb er).
4.
A urine's transparency or clarity is best assessed by
observing light through a recently mixed sample. Terms
used to report transparency include clear, hazy, cloudy, and
turbid.
5.
The specific gravity of a liquid is defined as the ratio of the
density of the substance being measured to the density of
water at a specified temperature. Urine specific gravity is a
measure of the am ount of solutes (elec trolyte s, ure a, etc.)
present in the urine sample. Specific gravity indicates how
dilute or concentrated is the specimen. The assigned
reference value of water is 1.000. Most authors consider
1.015-1.025 to be the normal urine specific gravity range
although the kidneys are capable of 1.001-1.030.
6.
The kidneys help to regulate the body's acid-base balance by
excreting excess acid or excess alkali. The accepted
method for routine measurement of urine pH reaction is by
mea ns of pH indicators.
7.
Other urine physical properties of volume, odor, and foam
are not routinely reported.
8.
Multistix or Chemstrips - chemical principles of procedures:
a.
Specific Gravity - check individual m anufa ctures
packa ge insert.
b.
pH The indicators methyl red and bromthymol blue
provide a b road rang e of co lors cov ering th e en tire
urinary pH range. Colors range from orange through
yellow and green to blue.
c.
Pro tein This test is base d on the protein-error-o f-
indicators principle; at a constant buffered pH, the
development of any green color is due to the presence of
protein. Colors range from yellow for Negative through
yellow-green, green to blue-green for Positive
reactions.
d.
Glucose This test is based on a double enzyme
reaction. The enzyme glucose oxidase catalyzes the
formation of gluconic acid and hydrogen peroxide from
the oxidation of glucose. The second enzyme,
peroxidase, catalyzes the reaction of hydrogen peroxide
with a potassium iodide chromogen to oxidize the
chromogen to colors ranging from green to brown. EXERCISE 1: Macroscopic Urinalysis
Urinalysis
4
e.
Ketones This test is base d on the deve lopm ent of a
purple c olor w hen aceto ace tic acid or a ceto ne reacts
with nitroprusside.
f.
Biliru bin T his test is based on the coupling of b ilirubin
with diazotized dichloroaniline in a strongly acid m edium .
The color ranges through various shades of tan.
g.
Blood This test is base d on the peroxidase-like activity
of hemoglobin or myoglobin which catalyzes the reaction
of cumene hydroperoxide and orthotolidine. The
resulting color ra nge s from oran ge th roug h gre en to dark
blue.
h.
Nitrite *Nitrite is formed in the bladder by the action of
certain bacteria on urinary nitrate. At an acid pH, the
nitrite reacts with p-arsanilic acid to form a diazonium
compound.
I.
Urobilinogen This test is based on the Ehrlich reaction
in which paradime thylaminob enzaldehyde reacts w ith
urobilinogen in a strongly acid medium to produce a
brown-orange color. * When there is no change of the
test strip co lor, the resu lt is usu ally reported as "No rmal,"
not negative.
j.
Leukocyte esterase* Rea ction as follows:
*Nitrite test and leukocyte esterase are not available on
all dip stix
URINE BACKUP TESTS
9.
Pro tein by Su lfos alicylic Ac id T he 3% sulfosalicy lic ac id
precipitates protein in solution, turning the urine specimen
milky. The degree of turbidity is graded from trace to 4+.
10.
Ketones b y Acetest reagent tablets Acetoacetic acid or
acetone in urine or blood will form a purple colored complex
with nitroprusside in the presence of glycine.
11.
Bilirubin by Ictotest reagent tablets The reaction is based
on the coupling of a unique solid diazonium salt with bilirubin
in acid m edium to give the blue o r purple reaction product.
12.
Glucose and other Reducing substances by Clinitest
reagent tablets for reducing sugars. This test is based on the
classic Benedict's copper re duction reaction. Co pper su lfate
rea ct w ith re ducing substances in urine , convertin g cupric
sulfate to cuprous oxide. Colors range from blue through
green to orange. This test is used to detect sugars other EXERCISE 1: Macroscopic Urinalysis
Urinalysis
5
than gluco se (i.e., lactos e an d ga lactose ).
Procedure
:
1.
Mix specim ens well and classify five (5) specimens for c olor.
Note any unusual colors and record.
2.
Visually inspect and classify the same five (5) specimens for
clarity. Be sure specimen has been well-mixed befo re
classifying.
3.
Determine the specific gravity of the five (5) specimens using
the AO TS meter. Before determining the s.g. of the five (5)
urines, check the refractometer's accuracy by measuring the
s.g. of a drop of deionized H
2
O (should be 1.000) and the
s.g. of a drop of 5% sodium chloride solution (should be
1.022 ± 0.001). If the s.g. of the deionized H
2
O and the
sodium chloride do not m atch w hat the y sh ould be, consult
the instructor for further directions.
4.
Determine the following chemical concentrations on the five
specimens using the Multistix reagent strips and the following
procedure:
a.
Mix the specimen.
b.
Completely immerse all reagent areas of the strip.
c.
Remove the reagent strip immediately and tap off any
excess urine.
d.