1. Leaving excess urine on the reagent strip
Answer: (C) Cause reagents to leach from the pads Leaving excess urine on the reagent strip can cause reagents to leach from the pads due to overhydration, which can lead to inaccurate results or runover between pads.
2. Failure to mix a specimen
Answer: (D) Both B and C
Failure to mix a urine specimen before testing can cause heavier elements like red blood cells (blood) and leukocytes to settle at the bottom. This results in inaccurate (falsely decreased) readings for these components on the reagent strip.
3. Testing a refrigerated specimen
Answer: (A) Enzymatic reactions
Testing a cold, refrigerated specimen can slow down enzymatic reactions on the reagent strip, such as those for glucose and leukocyte esterase, leading to falsely decreased results. Specimens should be warmed to room temperature before testing.
4. Longest reaction time
Answer: (C) Leukocyte esterase
The leukocyte esterase reaction on a standard reagent strip typically requires the longest reaction time (often 2 minutes) compared to bilirubin, pH, or glucose tests, to allow sufficient time for the reaction to occur and a color change to develop.
5. Quality control of reagent strips
Answer: (D) All of the above
Quality control (QC) of urine reagent strips involves using both positive and negative controls, performing QC per laboratory policy (e.g., daily or with new bottles), and when results are questionable, to ensure accuracy and reliability of results.
6. Protect the integrity of reagent strips
Answer: (A) Removing the desiccant from the bottle
Removing the desiccant packet from the reagent strip bottle should not be done, as its purpose is to absorb moisture and protect the integrity of the moisture-sensitive chemical pads. Storing in an opaque, tightly resealed bottle at room temperature protects them from light, moisture, and heat.
7. Principle of the reagent strip test for pH
Answer: (D) Double indicator reaction
The principle of the reagent strip test for pH is the double indicator reaction, typically using methyl red and bromthymol blue, which change color over different pH ranges to provide a broad spectrum of pH values.
8. A urine specimen with a pH of 9.0
Answer: (B) Should be re-collected
A urine pH of 9.0 is abnormally high and often indicates an improperly preserved specimen where bacteria have broken down urea into ammonia, making it highly alkaline. A fresh specimen should be collected to get an accurate reading.
9. Primary consideration associated with pH
Answer: (D) Both A and C
In the laboratory, primary considerations associated with urine pH are identifying urinary crystals (which form at specific pH ranges) and determining specimen acceptability (as an alkaline pH can indicate an old, unpreserved sample).
10. Indicate the source of the following proteinurias
10. A. Microalbuminuria
Answer: 2
Microalbuminuria is a sign of early renal (kidney) damage, particularly in conditions like diabetes mellitus and hypertension.
10. B. Acute-phase reactants
Answer: 1
Acute-phase reactants are proteins produced by the liver in response to inflammation or infection, causing prerenal proteinuria (protein originating before the kidneys).
10. C. Preeclampsia
Answer: 2
Preeclampsia is a condition during pregnancy characterized by hypertension and significant proteinuria, indicating renal involvement.
10. D. Vaginal inflammation
Answer: 3
Vaginal inflammation causes postrenal proteinuria, as the protein enters the urine after it has left the kidneys and urinary tract.
10. E. Multiple myeloma
Answer: 1
Multiple myeloma involves the overproduction of Bence Jones protein, which is filtered by the kidneys but originates in the blood (prerenal).
10. F. Orthostatic proteinuria
Answer: 2
Orthostatic (postural) proteinuria is a benign condition where protein is found in urine only when standing, indicating a renal cause related to kidney position.
10. G. Prostatitis
Answer: 3
Prostatitis (prostate inflammation) causes postrenal proteinuria, as the protein enters the urine from the lower urinary tract/reproductive system.
11. The principle of the protein error of indicators reaction
Answer: (B) Albumin accepts hydrogen ions from the indicator
The principle of the protein error of indicators reaction is that albumin (and other proteins) acts as a hydrogen ion acceptor in the presence of certain pH indicators at a constant pH, causing a color change that is interpreted as "protein".
12. All of the following will cause false-positive protein values except
Answer: (A) Microalbuminuria
Microalbuminuria is a true positive result for small amounts of albumin in the urine, not a false positive. Highly buffered alkaline urines, delayed removal of the strip, and contamination can all cause false positive readings.
13. A patient with a 2+ protein reading in the afternoon
Answer: (A) Positive for orthostatic proteinuria
A patient with a positive protein reading in the afternoon but a negative first morning specimen is positive for orthostatic (postural) proteinuria, a condition where protein appears in the urine only when in an upright position.
14. Testing for microalbuminuria is valuable for early detection of kidney disease and monitoring patients with
Answer: (D) All of the above
Testing for microalbuminuria is valuable for early detection of kidney disease and monitoring patients with hypertension, diabetes mellitus, and cardiovascular disease risk, as it indicates early kidney damage associated with these conditions.
15. The primary chemical on the reagent strip in the Micral-Test for microalbumin binds to
Answer: (B) Antihuman albumin antibody
The Micral-Test for microalbuminuria uses an antihuman albumin antibody conjugated to an enzyme to specifically detect and bind to small amounts of albumin in the urine.
16. All of the following are true for the ImmunoDip test for microalbumin except:
Answer: (C) Bound antibody migrates farther than unbound antibody
The ImmunoDip test uses an immunochromographic principle where blue latex particles coated with anti-human albumin antibodies are used. In this test, the unbound antibodies migrate farther up the strip than the bound antibodies, which are captured at the test line. Option C states the opposite of this principle, making it the incorrect statement.
17. The principle of the protein-high pad on the Multistix Pro reagent strip is the:
Answer: (C) Protein error of indicators
The protein-high pad on the Multistix Pro reagent strip utilizes the protein error of indicators principle to detect high levels of protein in urine.
18. Which of the following is not tested on the Multistix Pro reagent strip?
Answer: (D) Protein-high
The Multistix Pro reagent strip tests for urobilinogen, specific gravity, and creatinine, but not the protein-high pad, which is a separate test.
19. The principle of the protein-low reagent pad on the Multistix Pro is the:
Answer: (A) Binding of albumin to sulphonphthalein dye
The protein-low reagent pad on the Multistix Pro uses the binding of albumin to sulphonphthalein dye principle for detection.
20. The principle of the creatinine reagent pad on microalbumin reagent strips is the:
Answer: (B) Diazo reaction
The creatinine reagent pad on microalbumin reagent strips is based on the diazo reaction principle.
21. The purpose of performing an albumin:creatinine ratio is to:
Answer: (B) Correct for hydration in random specimens
The albumin:creatinine ratio is performed to correct for variations in hydration in random urine specimens, providing a more standardized measure of albumin excretion.
22. A patient with a normal blood glucose and a positive urine glucose should be further checked for:
Answer: (B) Renal disease
A positive urine glucose result with normal blood glucose levels suggests a potential issue with renal reabsorption, indicating the need to check for renal disease.
23. The principle of the reagent strip tests for glucose is the:
Answer: (C) Double sequential enzyme reaction
The reagent strip tests for glucose use a double sequential enzyme reaction involving glucose oxidase and peroxidase.
24. All of the following may produce false-negative glucose reactions except:
Answer: (A) Detergent contamination
Ascorbic acid, unpreserved specimens, and low urine temperature can all lead to false-negative glucose results. Detergent contamination, however, is not a typical cause of a false-negative reaction.
25. The primary reason for performing a Clinitest is to:
Answer: (C) Check for newborn galactosuria
While the Clinitest can confirm a positive reagent strip glucose result, its primary reason for use today is to check for the presence of other reducing sugars, such as in newborn galactosuria, as reagent strips are specific for glucose.
26. The three intermediate products of fat metabolism include all of the following except:
Answer: (B) Ketoacetic acid
The three intermediate products of fat metabolism (ketone bodies) are acetoacetic acid,
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-hydroxybutyric acid, and acetone. Ketoacetic acid is not a recognized intermediate product.
27. The most significant reagent strip test that is associated with a positive ketone result is:
Answer: (A) Glucose
A positive ketone result is most significantly associated with a positive glucose result, as both are indicators of uncontrolled diabetes mellitus.
28. The primary reagent in the reagent strip test for ketones is:
Answer: (D) Sodium nitroprusside
Sodium nitroprusside (or nitroferricyanide) is the primary reagent used in the reagent strip test for ketones, reacting with acetoacetic acid and acetone to produce a color change.
29. Ketonuria may be caused by all of the following except:
Answer: (A) Bacterial infections
Diabetic acidosis, starvation, and vomiting can all lead to ketonuria (ketones in the urine). Bacterial infections are not a typical cause.
30. Urinalysis is frequently performed on a patient with severe back and abdominal pain to check for:
Answer: (C) Hematuria
Severe back and abdominal pain, often associated with kidney stones or urinary tract issues, frequently prompts a urinalysis to check for hematuria (blood in the urine).
32. The principle of the reagent strip test for blood is based on the:
Answer: (B) Peroxidase activity of heme
33. A speckled pattern on the blood pad of the reagent strip indicates:
Answer: (A) Hematuria
34. List the following products of hemoglobin degradation in the correct order of metabolism by placing numbers 1 to 4 in the blank, where 1 indicates the beginning and 4 indicates the end product.
Answer:
A. Conjugated bilirubin: 2
B. Urobilinogen and stercobilinogen: 3
C. Urobilin: 4
D. Unconjugated bilirubin: 1
35. The principle of the reagent strip test for bilirubin is the:
Answer: (A) Diazo reaction
36. An elevated urine bilirubin with a normal urobilinogen is indicative of:
Answer: (D) Biliary obstruction
37. The primary cause of a false-negative bilirubin reaction is:
Answer: (C) Specimen exposure to light
38. The purpose of the special mat supplied with the Ictotest tablets is that:
Answer: (A) Bilirubin remains on the surface of the mat
39. The reagent in the Multistix reaction for urobilinogen is:
Answer: (C) p-Dimethylaminobenzaldehyde
40. The primary problem with urobilinogen tests using Ehrlich reagent is:
Answer: (D) All of the above
41. The reagent strip test for nitrite uses the:
Answer: (A) Greiss reaction
42. All of the following can cause a negative nitrite reading except:
Answer: (B) Gram-negative bacteria
43. A positive nitrite test and a negative leukocyte esterase test is an indication of a:
Answer: (B) Specimen with lysed leukocytes
44. All of the following can be detected by the leukocyte esterase reaction except:
Answer: (C) Lymphocytes
45. Screening tests for urinary infection combine the leukocyte esterase test with the test for:
Answer: (B) Nitrite
46. The principle of the leukocyte esterase reagent strip test uses a:
Answer: (C) Diazo reaction
47. The principle of the reagent strip test for specific gravity uses the dissociation constant of a(n):
Answer: (C) Polyelectrolyte
48. A specific gravity of 1.005 would produce the reagent strip color:
Answer: (A) Blue
49. Specific gravity readings on a reagent strip are affected by:
Answer: (D) All of the above
Case Studies and Clinical Situations
1. A patient taken to the emergency department after an episode of syncope has a fasting blood glucose level of 450 mg/dL. Results of the routine urinalysis are as follows:
a. What would be observed if this specimen were shaken?
Answer: (a) Foam
Explanation: A urine specimen with a 2+ ketone level and a slightly low protein level would likely produce some foam when shaken.
b. Explain the correlation between the patient's scheduled surgery and the normal urobilinogen.
Answer: (b) Normal urobilinogen is not directly related to scheduled surgery
Explanation: Urobilinogen levels relate to liver function and red blood cell breakdown, which typically wouldn't have a direct correlation with a general scheduled surgery.
c. If blood were drawn from this patient, how might the plasma appear?
Answer: (c) Clear
Explanation: The urinalysis indicates negative blood and negative bilirubin, suggesting no significant hemolysis or liver issues that would color the plasma.