Normally present in urine: elevated levels
may indicate liver abnormalities or excessive
destruction of RBC’s, e.g. in homolytic anemia.
urobilinogen should be considered alongside
billirubin as a differential diagnosis
Protein A positive result indicates renal disease, raised
blood pressure or urinary tract infection
pH Normal range 4 to 6. A pH above 7 suggests
states urine unsuitable for testing
Blood Presence in urine suggests serious renal or
urological disease, or renal tract infection
Monitors the concentrating and diluting power of
the kidney. Assists in the interpretation of other
Ketone May indicate uncontrolled diabetes or a reduced
Indicative of hepatic or biliary disease. Bilirubin
may appear in urine before other signs of
Glucose The most important cause of glucose in urine is
FIG. 5.11: Clinitek 50: The instrument
(Courtesy: Siemens Medical Solutions)
There’s no denying easy chemistry. ¾ Multistix GP
Clinitek® 50 Urine Analyzer (Fig. 5.11)
Dependable Results in Any Patient Setting
Combined with the Bayer market leading urinalysis strips,
Multistix, the Bayer Clinitek 50 provides the complete
urinalysis solution. Suitable for use in a wide range patient
settings, the Clinitek 50 provides on the spot, accurate
results that allowing on the spot clinical decisions.
1. Dip reasgent strip into sample and press start button
2. Blot side of reagent strip and place strip on instrument
3. Instrument analyzes, displays abnormally and prints
results at the rate of one test per minute (Fig. 5.14).
¾ The Clinitek 50 requires only 10 seconds of operators
time, meaning you can get on with caring for your
patient whilst the instrument does the test.
¾ Display prompts make the Clinitek 50 intuitive and
FIG. 5.13: Place reagent strip on the instrument feed table
FIG. 5.15: Clinitek 500 urinalysis instrument
FIG. 5.12: Dip the reagent strip FIG. 5.14: The instrument with printout
¾ Fast, reliable results available in 1 minute, giving a
printed record of the patients results.
Screens out non-infected urine samples so that only the
positives need to be referred for laboratory follow-up
A Wide Range of Test Parameters
Clinitek 50 is suitable for use with;
¾ Multistix lOSG Multistix 8SG
¾ See Figure 5.10 for etiological basis of positive results
Clinitek® 500 Urinalysis Instrument
In combination with the Bayer market leading, Multistix®
range, the Clinitek® 500 enables automated reading of strips
in high throughout settings (Fig. 5.15). Complimented
by a user friendly interface and comprehensive data
management it provides a discrete platform offering
accuracy of results and efficiency in workflow.
¾ 1 strip processed every 7 seconds
¾ Strip needs only to be placed in analyzer platform.
Continuous “load and capture”mechanism draws strip
¾ Strip automatically discarded into waste tray after
¾ Barcode reader for data entry.
• Easy to read touch screen display
• Operator screen guidance for processing
• Barcode reader for data entry.
¾ Accurate identification and flagging of abnormal data
¾ Two screening functions—confirmatory and microscopic
¾ Customizable testing and reporting to meet local needs
¾ Memory storage of 500 patient results and 200 control
• Print using on board printer
¾ Operator and patient ID facility.
A Wide Range of Test Parameters
Clinitek® 500 is suitable for use with:
Calcium in Urine (Sulkowitch Test)
Fasting or random samples may be tested. Before the
test, the patient should be on neutral low-calcium diet for
3 days. Collect 24 hours urine specimen. Mix equal parts
of urine and Sulkowitch reagent, let stand for 2–3 minutes
0 = No precipitate, no urine calcium; serum
1+ = Fine white cloud, normal urine and blood
2+ and 3+ = Thicker, coarser precipitate, raised urinary
4+ = Precipitate like milk, strongly positive.
• 100–250 mg/24 hours on average diet
• < 150 mg/24 hours on low calcium diet.
Most of the calcium discharged by the body is excreted
via stool. However, there is a small quantity of calcium
that is normally excreted in the urine, this varies with the
variation in dietary calcium. The 24 hours test is most often
required to determine the function of the parathyroid
gland, which maintains a balance between calcium and
phosphorus by means of parathormone.
Calcium in urine can also be estimated by using regular
serum biochemistry tests—OCPC or Arsenazo method.
• Hyperparathyroidism (results in constant 3 + to
• Primary cancers of breast and lung
• Myeloma with bone metastasis
2. Increased urinary calcium usually accompanies
elevated blood calcium levels.
3. Calcium excretion greater than intake is always
excessive, and excretion above 400–500 mg/24 h is
4. Increased levels of calcium occur whenever calcium is
mobilized from the bone, as in metastatic cancer and
prolonged skeletal mobilization.
5. When calcium is excreted in increasing amounts, a
potential for nephrolithiasis or nephrocalcinosis is
1. Hypoparathyroidism (hypocalcemia caused by
hypoparathyroidism is usually associated with a
2. Vitamin D deficiency (vitamin D is essential for
a. Falsely high values are seen in:
• High sodium and magnesium intake
• Levels are often high immediately after meals
– Nandrolone, in some cancer patients.
B. False negative (lowered) values are seen in
1. Urine calcium test is not a substitute for serum
calcium, it can, however, be done in an emergency.
Hypercalcemia can be life threatening.
2. Low urinary calcium patients should be observed for
3. The first sign of calcium imbalance may be the
occurrence of pathological fractures that can be related
Serotonin (5-Hydroxytryptamine)
Carcinoids: (Argentaffinomas) may produce serotonin,
which is metabolized to 5-hydroxy-indole acetic acid (5-
HIAA). Presence of this compound in urine in more than
traces indicates malignant carcinoid metastatic to the liver.
Acidify 2 mL of filtered urine with 2 drops of 10% HCl and
extract twice with 20–25 mL of ether. Evaporate the dry
residue in 1 mL of 0.1 N HCl. Add 1 mL Ehrlich’s reagent.
Boil for 2–3 minutes. A distinct blue color indicates the
presence of 5-HIAA in abnormal amounts in urine.
For screening purposes, a random test may be enough.
Serotonin is a vasoconstricting hormone produced
normally by argentaffin cells of the GI tract. The principal
function of the cells is to regulate smooth muscle
contraction and peristalsis. In carcinoid tumor (tumor of
denatured product of serotonin.
1. No bananas, pineapples, tomatoes, eggplants, or
avocados to be consumed during the 24 hours test
because they contain serotonin.
2. A 24 hours urine container with preservative is labeled
with the name of patient, test and date.
3. General instructions for 24 hours sample collection
1. Levels in excess of 100 mg per 24 hours are indicative
of large carcinoid tumor, especially when metastatic.
However, this increase is found only in 5–7% cases of
2. Levels between 10 mg and 100 mg per 24 hours may
• Severe pain of sciatica or skeletal and smooth
1. Bananas, pineapples, plums, walnut, and avocados
may increase 5-HIAA levels, for all of them contain
2. Drugs that may lead to false-positive result
Drugs that may falsely decrease 5-HIAA levels:
84 Concise Book of Medical Laboratory Technology: Methods and Interpretations ¾ Heparin
Ideally, the patient should take no drugs for 72 hours
To 5 mL of urine, add 2 mL of 5% sodium cyanide
solution and let them react for 10 minutes. Add 5 drops
of 5% sodium nitroprusside solution and mix thoroughly.
Cystine produces a magenta color. If no cystine is present,
a pale brown or pale pink color results. All solutions should
be freshly prepared. Also, examine the urinary sediment
for cystine crystals. Urinary cystine is raised in cystinurias.
Quantitative : Children under 8 years:
Individuals above 8 years : 7–28 mg/h.
These tests of urine are useful in the differential
diagnosis of cystinuria, an inherited disease from
cystinosis. Cystinuria is a hereditary disease, characterized
by bladder calculi. In cystinosis, cystine is deposited in
1. Cystinuria (up to 20 times normal) in which there
is excessive urinary excretion of lysine, ornithine,
2. Cystinosis (no excess of lysine, arginine or ornithine).
Take equal parts of urine and ether, cloudiness due to fat
disappears, decant ether onto a watch glass, evaporate, fat
leaves a greasy deposit. Fat may be seen microscopically.
Hereditary Metabolic Disorders
Errors of Carbohydrate Metabolism
1. Galactosuria: Positive test for reducing substance
(Benedict’s qualitative). Negative glucose-oxidase test.
2. Pentosuria: Positive Benedict’s qualitative test.
Negative glucose-oxidase test. Positive orcinyl-HCl
Errors of Amino Acid Metabolism
1. Cystinuria: Positive cyanide-nitroprusside test. Cystine
2. Fanconi’s syndrome: Positive glucose-oxidase test.
Paper chromatography for amino acids.
3. Wilson’s disease: Positive glucose-oxidase test. Paper
chromatography for amino acids.
4. Phenylketonuria: Positive ferric chloride test.
5. Hartnup disease: Paper chromatography.
6. Alkaptonuria (Homogentisic acid): Positive Benedict’s
7. Tyrosinosis: Paper chromatography. Positive Millon test.
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