1.
After receiving a 24 hour urine for quantitative total protein analysis, the technician must first:
Correct Answer
D. Measure the total volume
Explanation
Measure the total volume of the sample before removing an aliquot. To calculate the total protein, measure the protein of an aliquot to learn the mg/dL, then multiply that answer by the number of dL in the 24 hour collection
2.
False results in urobilinogen testing may occur if the urine specimen is:
Correct Answer
A. Exposed to light
Explanation
Urobilinogen is degraded by light
3.
A clean-catch urine is submitted to the laboratory for routine urinalysis and culture. The routine urinalysis is done first, and 3 hours later, the specimen is sent to the microbiology department for culture. The specimen should:
Correct Answer
B. Be rejected due to time delay
Explanation
It is common practice to share samples between the microbiology department and urinalysis department. Ideally, the culture is set up first to prevent contamination. If that is not feasible timewise, the sample should be aliquotted using aseptic technique, and refrigerated until it can be cultured.
4.
Which of the following urine results is most apt to be changed by proloinged exposure to light?
Correct Answer
D. Bilirubin
Explanation
Bilirubin is degraded by light. The other analytes will not be affected.
5.
Urine samples should be examined within 1 hour of voiding because:
Correct Answer
C. Bacterial contamination will cause alkalinization of the urine
Explanation
Evaluate each statement. (a) is incorrect because these cells don't agglutinate. (b) is partially correct, but urobilinogen decreases in light. (c) is true, bacterial overgrowth does lead to an alkaline urine. (d) is false, ketones are produced by fat metabolism in the patient
6.
The following results were obtained one a urine speciment at 8:00 am:
pH: 5.5
protein: 2+
glucose: 3+
ketones: 3+
blood: negative
bilirubin: positive
nitrite: positive
If this urine speciment was stored uncapped at 5 degrees C without preservation and retested at 2pm, which of the following test results would be changed due to these storage conditions?
Correct Answer
B. Ketones
Explanation
The sample is mistreated by being uncapped. It is refrigerated, which will prevent bacteria from reproducing (so (d) is incorrect), and from metabolizing glucose (so (a) is incorrect). Ketones can evaporate, but protein will not.
7.
A urine speciment comes to the laboratory 7 hours after it is obtained. It is acceptable for culture only if the specimen has been stored:
Correct Answer
B. At 4-7 degrees C
Explanation
Storage must inhibit bacterial growth but not kill the bacteria. Freezing and additives are not acceptable. The most commonly used method of preservation is refrigeration.
8.
Which of the following would be affected by allowing a urine specimen to remain at room temperature for 3 hours before analysis?
Correct Answer
C. pH
Explanation
Allowing a urine specimen to remain at room temperature for 3 hours before analysis can affect the pH level. pH is a measure of the acidity or alkalinity of a substance, and it can change over time due to various factors such as bacterial growth and chemical reactions. Therefore, if a urine specimen is left at room temperature for an extended period, it can lead to alterations in pH levels, potentially impacting the accuracy of the analysis.
9.
A 24-hour urine from a man who had no evidence of kidney impairment was sent to the laboratory for hormone determination. The volume was 600 mL, but there was some question as to the completeness of the 24-hour collection. The next step would be to :
Correct Answer
D. Check the creatinine level; if it is >1g, do the procedure
Explanation
The correct answer is to check the creatinine level; if it is >1g, do the procedure. This is because the creatinine level in the urine can be used as a marker for the completeness of a 24-hour urine collection. If the creatinine level is greater than 1g, it suggests that the collection was incomplete, and therefore, the hormone determination should not be performed. Instead, the procedure should be repeated to ensure a complete collection.
10.
Failure to observe RBC casts in a urine specimen can be caused by:
Correct Answer
B. Centrifuging an unmixed specimen
Explanation
Failure to observe RBC casts in a urine specimen can be caused by centrifuging an unmixed specimen. When a urine specimen is not properly mixed before centrifugation, the RBC casts may settle at the bottom and not be evenly distributed in the sediment. As a result, when examining the sediment under the microscope, the RBC casts may not be present or may be difficult to identify.
11.
EGFR calculated by the MDRD formula takes into account the age, BUN, race, albumin and what else for its calculation?
Correct Answer
C. Creatinine
Explanation
The eGFR calculated by the MDRD formula takes into account the age, BUN, race, albumin, and creatinine for its calculation. Creatinine is a waste product that is produced by the muscles and filtered by the kidneys. It is a commonly used marker to estimate kidney function. The MDRD formula combines these factors to estimate the glomerular filtration rate (GFR), which is a measure of how well the kidneys are functioning. Therefore, creatinine is an important component in the calculation of eGFR using the MDRD formula.
12.
The creatinine clearance is reported in:
Correct Answer
C. ML/min
Explanation
The creatinine clearance is reported in mL/min because it measures the rate at which the kidneys are able to filter creatinine from the blood. Creatinine is a waste product that is produced by the muscles and excreted by the kidneys. By measuring the amount of creatinine cleared from the blood in a specific amount of time, mL/min provides a standardized unit to assess kidney function. This measurement is commonly used in clinical practice to evaluate renal health and monitor the progression of kidney diseases.
13.
Microalbumin can be measured by a random urine collection. An increase microalbumin is predictive of:
Correct Answer
B. NepHropathy
Explanation
An increase in microalbumin levels in a random urine collection is predictive of nephropathy. Nephropathy refers to kidney damage or disease, and an increase in microalbumin indicates that the kidneys are not functioning properly. This can be a sign of nephropathy, which can be caused by various factors such as diabetes mellitus, hypertension, or nephrotic syndrome. Therefore, an increase in microalbumin levels can be used as an indicator of nephropathy.
14.
A patient with uncontrolled diabetes mellitus will most likely have:
Correct Answer
A. Pale urine with a high specific gravity
Explanation
Uncontrolled diabetes mellitus can lead to increased blood glucose levels, which results in excess glucose being filtered by the kidneys and excreted in the urine. This excess glucose in the urine causes an osmotic diuresis, leading to increased urine production. However, despite the increased volume of urine, the urine may appear pale because the high glucose levels can cause dehydration. Additionally, the high glucose levels in the urine contribute to a high specific gravity, indicating concentrated urine.
15.
While performing an analysis of a baby's urine, the technologist notices the specimen to have a "mousy" odor. Of the following substances that may be excreted in urine, the one that most characteristically produces this odor is:
Correct Answer
A. pHenylpyruvic acid
Explanation
Phenylpyruvic acid is the correct answer because it is associated with a condition called phenylketonuria (PKU), which is characterized by the inability to break down the amino acid phenylalanine. When phenylalanine is not properly metabolized, it can lead to the accumulation of phenylpyruvic acid in the body, which can then be excreted in the urine. This buildup of phenylpyruvic acid gives the urine a distinct "mousy" odor, making it the substance most characteristically associated with this odor. Acetone, coliform bacilli, and porphyrin are not typically associated with a "mousy" odor in urine.
16.
An ammonia-like odor is characteristically associated with urine from patients who:
Correct Answer
C. Have an infection with Proteus sp
Explanation
An ammonia-like odor in urine is typically associated with an infection caused by the bacteria Proteus sp. This bacterium produces an enzyme called urease, which breaks down urea in the urine into ammonia, resulting in the distinct odor. Other conditions mentioned in the options such as diabetes, hepatitis, and yeast infections may have their own characteristic symptoms or odors, but they are not specifically associated with an ammonia-like odor in urine.
17.
Urine that develops a port wine color after standing may contain:
Correct Answer
B. PorpHyrins
Explanation
Urine that develops a port wine color after standing may contain porphyrins. Porphyrins are a group of organic compounds that are involved in the production of heme, a component of hemoglobin. When there is an excess of porphyrins in the urine, it can lead to a dark red or port wine color. This can be seen in conditions such as porphyria, which is a group of rare genetic disorders that affect the production of heme.
18.
Acid urine that contains hemoglobin will darken on standing due to the formation of:
Correct Answer
C. Methemoglobin
Explanation
Acid urine that contains hemoglobin will darken on standing due to the formation of methemoglobin. Methemoglobin is a form of hemoglobin that has been oxidized, resulting in a brown color. This oxidation process occurs naturally over time when hemoglobin is exposed to certain chemicals or conditions, such as acidic urine. The formation of methemoglobin is responsible for the darkening of the urine.
19.
Urine from a 50-year-old man was noted to turn dark red on standing. This change is caused by:
Correct Answer
B. PorpHyrins
Explanation
The dark red color of urine from a 50-year-old man on standing is caused by porphyrins. Porphyrins are a group of organic compounds that are involved in the synthesis of heme, which is a component of hemoglobin. When there is an excess of porphyrins in the body, they can be excreted in the urine, leading to a dark red color. This condition is known as porphyria, which can be caused by genetic disorders or certain medications.
20.
The clarity of a urine sample should be determined:
Correct Answer
B. Following thorough mixing of the specimen
Explanation
The clarity of a urine sample should be determined following thorough mixing of the specimen. Thorough mixing ensures that any sediment or particles in the urine are evenly distributed, allowing for a more accurate assessment of its clarity. This step is important because the presence of cloudiness or turbidity in the urine can indicate the presence of abnormal substances such as bacteria, red or white blood cells, or crystals. Therefore, by thoroughly mixing the specimen before evaluating its clarity, healthcare professionals can obtain a more reliable result.
21.
Milky urine from a 24-year-old woman would most likely contain:
Correct Answer
B. Many white blood cells
Explanation
Milky urine from a 24-year-old woman would most likely contain many white blood cells. This can indicate the presence of an infection in the urinary tract or kidneys. White blood cells are a part of the body's immune response and their increased presence in the urine suggests an inflammatory process. It is important for the woman to seek medical attention to determine the cause of the infection and receive appropriate treatment.
22.
A brown-black urine would most likely contain:
Correct Answer
C. Melanin
Explanation
A brown-black urine would most likely contain melanin. Melanin is a pigment that gives color to the skin, hair, and eyes. It is produced by special cells called melanocytes. In certain conditions or diseases, excess melanin can be excreted through urine, resulting in a dark brown or black color. Bile pigment, porphyrins, and blood cells are also possible causes of discoloration in urine, but melanin is the most likely explanation for a brown-black color.
23.
The yellow color of urine is primarily due to:
Correct Answer
A. Urochrome pigment
Explanation
The yellow color of urine is primarily due to the presence of urochrome pigment. Urochrome is a waste product formed from the breakdown of hemoglobin, the protein responsible for carrying oxygen in red blood cells. As the body metabolizes hemoglobin, urochrome is produced and excreted in the urine, giving it its characteristic yellow color. Methemoglobin, bilirubin, and homogenistic acid are not directly responsible for the yellow color of urine. Methemoglobin is an altered form of hemoglobin, bilirubin is a yellow pigment produced from the breakdown of red blood cells, and homogenistic acid is a metabolic byproduct associated with a rare genetic disorder called alkaptonuria.
24.
Red urine may be due to:
Correct Answer
C. Myoglobin
Explanation
Red urine may be due to myoglobin. Myoglobin is a protein found in the muscles, and its presence in the urine can indicate muscle damage or injury. When muscle cells are damaged, myoglobin is released into the bloodstream and eventually filtered by the kidneys, leading to its presence in the urine. This can occur in conditions such as rhabdomyolysis, which is characterized by the breakdown of muscle tissue. The presence of myoglobin in the urine gives it a red or reddish-brown color.
25.
A urine specimen collected on an apparently healthy 25-year-old man shortly after he finished eating lunch was cloudy by showed some normal results on a multiple reagent strip analysis. The most likely cause of the turbidity is:
Correct Answer
D. pHospHates
Explanation
The cloudy urine specimen in an apparently healthy individual after lunch is most likely caused by phosphates. Phosphates can form crystals in the urine when it is alkaline, leading to turbidity. The presence of normal results on the multiple reagent strip analysis suggests that other factors such as infection or inflammation are not likely causes of the turbidity. Fat, white blood cells, and urates are less likely to cause turbidity in this scenario.
26.
In which of the following metabolic diseases will urine turn dark brown to black upon standing?
Correct Answer
B. Alkaptonuria
Explanation
Alkaptonuria is a metabolic disease in which the body cannot properly break down an amino acid called tyrosine. As a result, a substance called homogentisic acid accumulates in the body and is excreted in urine. When this urine is exposed to air and allowed to stand, it oxidizes and turns dark brown to black in color. This is a characteristic feature of alkaptonuria. Phenylketonuria, maple syrup disease, and aminoaciduria do not typically cause urine to turn dark brown to black upon standing.
27.
Urine osmolality is related to:
Correct Answer
C. Specific gravity
Explanation
Urine osmolality is related to specific gravity because specific gravity is a measure of the concentration of solutes in urine. Osmolality refers to the concentration of solutes in a solution, and urine osmolality is a measure of the concentration of solutes in urine. Therefore, the specific gravity of urine can provide information about the osmolality of urine, indicating the concentration of solutes present in the urine sample.
28.
Urine specific gravity is an index of the ability of the kidney to:
Correct Answer
B. Concentrate the urine
Explanation
Urine specific gravity is a measure of the concentration of solutes in the urine compared to pure water. A higher specific gravity indicates a more concentrated urine, while a lower specific gravity indicates a more dilute urine. Therefore, the correct answer is "concentrate the urine." This ability is important for the kidneys to regulate the body's water balance and excrete waste products effectively.
29.
Osmolality is the measure of:
Correct Answer
A. Dissolved particles, including ions
Explanation
Osmolality is a measure of the concentration of dissolved particles in a solution, including both ions and undissociated molecules. It provides information about the number of solute particles present in a given volume of solvent. Osmolality is not influenced by the size of the molecules, but rather focuses on the total number of particles in solution. Therefore, the correct answer is that osmolality measures dissolved particles, including ions.
30.
A patient urine sample has an increased protein and a high specific gravity. Which of the following would be a more accurate measure of urine concentration?
Correct Answer
A. Osmolality
Explanation
Osmolality is a more accurate measure of urine concentration because it measures the concentration of all solutes in the urine, including proteins and other substances, regardless of their molecular weight. Specific gravity, on the other hand, only measures the density of the urine compared to water and can be influenced by factors other than solute concentration. Ketones, refractive index, and pH are not directly related to urine concentration.
31.
To prepare a solution appropriate for quality control of the refractometer, a technician should use:
Correct Answer
C. Sodium chloride with a specific gravity of 1.022
Explanation
The refractometer is a device used to measure the refractive index of a substance, which is related to its specific gravity. In order to calibrate the refractometer for quality control, the technician should use a substance with a known specific gravity. Among the options given, only sodium chloride with a specific gravity of 1.022 is suitable for this purpose. Urea, water, and calcium chloride do not have the specific gravity required for calibration.
32.
A urine's specific gravity is directly proportional it its:
Correct Answer
B. Dissolved solids
Explanation
The specific gravity of urine refers to its density compared to the density of water. Dissolved solids in urine, such as electrolytes, minerals, and waste products, contribute to its density and therefore affect its specific gravity. The higher the concentration of dissolved solids in urine, the higher its specific gravity will be. Therefore, the correct answer is dissolved solids.
33.
Isosthenuria is associated with a specific gravity which is usually:
Correct Answer
C. Fixed around 1.010
Explanation
Isosthenuria refers to a condition where the urine has a fixed specific gravity around 1.010. This means that the concentration of solutes in the urine is balanced, neither too dilute nor too concentrated. Isosthenuria can occur in conditions such as diabetes insipidus or chronic renal failure, where the kidneys are unable to properly concentrate or dilute the urine. A fixed specific gravity around 1.010 indicates impaired kidney function and the inability to regulate urine concentration effectively.
34.
The fluid leaving the glomerulus normally has a specific gravity of:
Correct Answer
B. 1.010
Explanation
The specific gravity of the fluid leaving the glomerulus is 1.010. Specific gravity is a measure of the density of a substance compared to the density of water. A specific gravity of 1.010 indicates that the fluid leaving the glomerulus is slightly more dense than water. This is important because the glomerulus is responsible for filtering waste products from the blood and forming urine. The specific gravity of urine can vary depending on hydration levels and other factors, but a specific gravity of 1.010 is considered within the normal range.
35.
An antidiuretic hormone deficiency is associated with a:
Correct Answer
B. Low specific gravity
Explanation
An antidiuretic hormone deficiency leads to a decrease in the reabsorption of water in the kidneys, resulting in increased urine production and a diluted urine. This leads to a low specific gravity, as specific gravity measures the concentration of solutes in urine.
36.
Use of a refractometer over a urinometer is preferred due to the fact that the refractometer uses:
Correct Answer
C. Small volume of urine and compensates for temperature
Explanation
A refractometer is preferred over a urinometer because it uses a small volume of urine and compensates for temperature. This means that it requires less urine for testing and takes into account the temperature of the urine sample, which can affect the accuracy of the results. By using a small volume of urine, it is also more convenient and less invasive for the patient.
37.
Calibration of refractometers is done by measuring the specific gravity of distilled water and:
Correct Answer
C. Sodium chloride
Explanation
Refractometers are instruments used to measure the refractive index of a substance, which is related to its specific gravity. Calibration is necessary to ensure accurate measurements. In this case, the specific gravity of distilled water is measured, and sodium chloride is used as a calibration standard. Sodium chloride has a known specific gravity, so by comparing the refractive index of the sodium chloride solution to that of distilled water, the refractometer can be calibrated accurately. Protein, glucose, and urea are not commonly used for calibration purposes in refractometers.
38.
The method of choice for performing a specific gravity measurement of urine following administration of x-ray contrast dyes is:
Correct Answer
A. Reagent strip
Explanation
The correct answer is reagent strip. Reagent strips are commonly used for specific gravity measurements in urine analysis. They contain chemical reagents that react with the urine sample and produce color changes or other visible indicators. These strips are easy to use, cost-effective, and provide quick results. In the case of urine samples with x-ray contrast dyes, reagent strips can still accurately measure specific gravity without interference from the dyes.
39.
Which of the following urinary parameters are measured during the course of concentration and dilution tests to assess renal tubular function?
Correct Answer
B. Osmolality and specific gravity
Explanation
Osmolality and specific gravity are measured during concentration and dilution tests to assess renal tubular function. Osmolality measures the concentration of solutes in urine, which helps determine the kidney's ability to concentrate or dilute urine. Specific gravity measures the density of urine, which provides information about the kidney's ability to maintain water balance. Urea, nitrogen, creatinine, sodium, and chloride are also important parameters in assessing renal function, but they are not specifically measured during concentration and dilution tests to assess renal tubular function.
40.
Refractive index is a comparison of:
Correct Answer
B. Light velocity in air to light velocity in solutions
Explanation
Light bends when it hits the surface of the liquid, because the light slows down its velocity. This is called refraction. The degree that the light bends is the refractive index.
41.
Which of the following can give a false-negative urine protein reading?
Correct Answer
D. Very dilute urine
Explanation
Very dilute urine can give a false-negative urine protein reading because when urine is highly diluted, the concentration of proteins in the sample may be too low to be detected by the test. This can lead to a false-negative result, indicating the absence of protein in the urine when it may actually be present.
42.
The pH of a urine specimen measures the:
Correct Answer
B. Free hydrogen ions
Explanation
The pH of a urine specimen measures the concentration of free hydrogen ions in the urine. pH is a measure of the acidity or alkalinity of a solution, and it is determined by the concentration of hydrogen ions present. In the case of urine, the pH level can provide information about the body's acid-base balance and the functioning of the kidneys. By measuring the concentration of free hydrogen ions, healthcare professionals can assess the acidity or alkalinity of the urine sample, which can be indicative of certain health conditions or the effectiveness of certain treatments.
43.
Upon standing at room temperature, a urine pH typically:
Correct Answer
B. Increases
Explanation
When urine is left standing at room temperature, there is a natural process called urea hydrolysis that occurs. Urea hydrolysis leads to the breakdown of urea into ammonia and carbon dioxide. The presence of ammonia increases the alkalinity of the urine, causing the pH to increase. Therefore, the correct answer is "increases".
44.
Urine reagent strips should be stored in a(n):
Correct Answer
C. Cool dry area
Explanation
Urine reagent strips should be stored in a cool dry area to maintain their effectiveness. Storing them in a refrigerator or incubator can cause moisture to accumulate on the strips, potentially leading to inaccurate results. Additionally, storing them in an open jar exposed to air can also affect their quality and reliability. Therefore, a cool dry area is the most suitable storage condition for urine reagent strips.
45.
The principle of the reagent strip test for urine protein depends on:
Correct Answer
B. Protein error of indicators
Explanation
The principle of the reagent strip test for urine protein relies on the concept of protein error of indicators. This means that certain indicators used in the test can react with substances other than protein, leading to a false positive or false negative result. The indicators used in the test can be affected by factors such as pH, temperature, and the presence of other substances in the urine, causing inaccurate protein measurements. Therefore, the correct answer is protein error of indicators.
46.
The protein section of the urine reagent strip is most sensitive to:
Correct Answer
A. Albumin
Explanation
Albumin is the correct answer because it is the most common protein found in urine and is a sensitive indicator of kidney damage or dysfunction. Elevated levels of albumin in the urine, known as albuminuria, can be a sign of conditions such as diabetes, hypertension, or kidney disease. The urine reagent strip is specifically designed to detect albumin, making it the most sensitive protein to be detected in urine samples. Mucoprotein, Bence Jones protein, and globulin are also proteins that can be present in urine, but albumin is the most sensitive to detect using the reagent strip.
47.
Routine screening of urine samples for glycosuria is performed primarity to detect:
Correct Answer
A. Glucose
Explanation
Routine screening of urine samples for glycosuria is performed primarily to detect the presence of glucose. Glycosuria refers to the abnormal presence of glucose in the urine, which can be an indication of high blood sugar levels or diabetes. By detecting glucose in the urine, healthcare professionals can identify individuals who may have undiagnosed diabetes or need further evaluation and treatment for their blood sugar levels. This screening helps in early detection and management of diabetes, preventing complications associated with uncontrolled blood sugar levels.
48.
Which of the following reagents is used to react with ketones in the urine?
Correct Answer
A. Sodium nitroprusside
Explanation
Sodium nitroprusside is used to react with ketones in the urine. Ketones are a class of organic compounds that are produced when the body breaks down fat for energy. In certain conditions such as diabetes or starvation, ketones can accumulate in the urine. Sodium nitroprusside is a reagent that reacts specifically with ketones, producing a color change. This reaction is often used in diagnostic tests to detect the presence of ketones in urine samples. Acetoacetic acid, acetone, and beta-hydroxybutyric acid are all types of ketones, but they are not the reagents used to react with ketones in the urine.
49.
A test area of a urine reagent strip is impregnated with only sodium nitroprusside. This section will react with:
Correct Answer
A. Acetoacetic (diacetic) acid
Explanation
The test area of the urine reagent strip is impregnated with sodium nitroprusside, which is known to react specifically with acetoacetic (diacetic) acid. This means that when acetoacetic acid is present in the urine sample, it will react with the sodium nitroprusside on the strip, causing a color change or other detectable reaction. The other substances listed, leukocyte estrase, beta-hydroxybutyric acid, and ferric chloride, do not have a specific reaction with sodium nitroprusside and therefore would not produce a detectable result on the test strip.
50.
A reagent strip area impregnated with stabilized, diazotized 2, 4-dichloroaniline will yield a positive reaction with:
Correct Answer
A. Bilirubin
Explanation
The reagent strip area impregnated with stabilized, diazotized 2, 4-dichloroaniline will yield a positive reaction with bilirubin. This is because diazotized 2, 4-dichloroaniline reacts with bilirubin to form a colored compound, indicating the presence of bilirubin in the sample. Hemoglobin, ketones, and urobilinogen do not react with this reagent strip, so they would not yield a positive reaction.