AUBF Chemical Analysis Part 1

Fill in the blank: The chemical examination of urine uses ________ reagent strips to detect analytes.

dry.

True or False: The chemical examination of urine only tests for glucose and protein.

False.

Identify the term: A firm plastic strip with pads impregnated with chemicals that react with urine.

Reagent strip.

What is the purpose of reagent strips in urinalysis?

To detect specific chemical analytes in urine.

Fill in the blank: Reagent strips must be stored in a ________, dry container.

cool.

True or False: Reagent strips should be exposed to moisture and volatile fumes.

False.

What is the recommended storage temperature for reagent strips?

Room temperature below 30°C.

Fill in the blank: Do not use reagent strips past their ________ date.

expiration.

True or False: Each test area on the reagent strip is specific to a particular analyte.

True.

Identify the type of strip that uses ethylene glycol-bis-tetraacetic acid for specific gravity measurement.

Chemstrip.

What reagent is used in Multistix for specific gravity?

Poly (methyl vinyl ether/maleic anhydride).

True or False: Specific gravity pad turns from yellow to blue as SG increases.

False.

Fill in the blank: The color change range for SG is from ________ to ________.

Blue (1.000) to Yellow (1.030).

What is the sensitivity range of the SG reagent pad?

1.000 to 1.030.

True or False: Protein concentration above 100 mg/dL may give a false positive SG.

True.

Identify one condition that may cause a false positive specific gravity.

Ketoacidosis.

Fill in the blank: Highly alkaline urine with pH ≥ ________ can cause false negative SG results.

6.5.

True or False: For Multistix, if pH ≥ 6.5, 0.005 must be added to SG reading.

True.

What is the clinical significance of SG in monitoring hydration?

It helps assess hydration and renal concentration ability.

Identify the condition characterized by a low SG due to inability to concentrate urine.

Diabetes insipidus.

True or False: SG helps determine if a urine specimen is too dilute.

True.

What is the reaction principle of the pH reagent pad?

Double indicator system.

Identify the two indicators used in the pH pad of reagent strips.

Methyl red and bromthymol blue.

True or False: The pH pad changes from orange to green to blue.

True.

Fill in the blank: pH values range from ________ to ________ on the reagent strip.

5.0 to 8.5.

What is the main clinical significance of pH in urine analysis?

Assessing acid-base regulation.

Identify one clinical application of urine pH testing.

Evaluation of renal tubular acidosis.

True or False: A urine pH of 4.0 or 9.0 is normal and doesn't need verification.

False.

What confirms an abnormal pH outside of reagent strip range?

pH meter.

Identify the test principle for protein detection in urine.

Protein error of indicators.

True or False: Protein pad detects both albumin and globulins equally.

False.

Fill in the blank: The protein reagent pad is most sensitive to ________.

Albumin.

What is the color change on the protein pad from negative to positive?

Yellow to Green to Blue.

What are the reagents used in Multistix for protein?

Tetrabromophenol blue and buffer.

True or False: The protein reagent pad has a sensitivity of 15-30 mg/dL albumin.

True.

Identify one cause of false positive protein test in alkaline urine.

Contamination with disinfectants.

True or False: Blood contamination will not interfere with protein pad reading.

False.

Fill in the blank: The SSA test can be used to confirm ________ in urine.

Protein.

Identify the principle behind the SSA confirmatory test.

Protein precipitation.

True or False: Sulfosalicylic acid causes protein to coagulate and precipitate.

True.

What causes a turbid result in SSA test?

Presence of protein.

Fill in the blank: The most common sugar detected in urine is ________.

Glucose.

True or False: The glucose pad is based on a double sequential enzyme reaction.

True.

Identify the enzymes used in the glucose reagent pad.

Glucose oxidase and peroxidase.

What is the indicator used in the glucose test pad?

Potassium iodide.

Fill in the blank: Glucose reagent pad sensitivity is ________ mg/dL.

75-125.

True or False: Reducing substances can cause false positive glucose pad results.

False.

What test is used to detect non-glucose reducing sugars?

Clinitest.

Identify one cause of false negative glucose result.

High ascorbic acid.

True or False: High ketone levels interfere with the glucose pad.

True.

Fill in the blank: The confirmatory test for reducing substances is the ________.

Clinitest.

What is the principle behind the Clinitest?

Copper reduction.

Identify the reagent used in Clinitest tablets.

Copper sulfate.

True or False: Clinitest can detect all reducing sugars.

True.

Fill in the blank: A ________ reaction in Clinitest indicates high glucose or other reducing sugars.

Pass-through.

Identify the color change in a positive Clinitest.

Blue to green to orange/red.

What is the clinical significance of glucosuria?

Possible diabetes mellitus.

True or False: Glucosuria always indicates diabetes mellitus.

False.

Identify a condition that may cause transient glucosuria.

Stress.

Fill in the blank: Ketones are intermediate products of ________ metabolism.

Fat.

Identify the three ketones found in urine.

Acetone, acetoacetic acid, beta-hydroxybutyric acid.

True or False: The reagent strip only detects beta-hydroxybutyric acid.

False.

What ketone is primarily detected by the reagent strip?

Acetoacetic acid.

Identify the reagent used in the ketone pad.

Sodium nitroprusside.

Fill in the blank: A purple color on the ketone pad indicates a ________ result.

Positive.

True or False: Ketones in urine can suggest diabetic ketoacidosis.

True.

Identify one non-diabetic condition that causes ketonuria.

Starvation.

What can cause false positives in the ketone test pad?

Levodopa or medications with sulfhydryl groups.

Fill in the blank: Hematuria is the presence of ________ in urine.

Intact RBCs.

What is hemoglobinuria?

Presence of free hemoglobin in urine.

True or False: Myoglobin can also react with the blood pad on the reagent strip.

True.

Identify the principle of the blood reagent pad.

Pseudoperoxidase activity of hemoglobin.

What color change indicates blood in urine?

Yellow to green to blue.

Fill in the blank: The blood pad uses a chromogen such as ________.

Tetramethylbenzidine.

True or False: A speckled pad indicates hematuria.

True.

Identify one cause of hemoglobinuria.

Hemolytic anemia.

What causes myoglobinuria?

Muscle injury or trauma.

True or False: Ascorbic acid can cause false negative blood test.

True.

Fill in the blank: The most frequent cause of positive blood test is ________.

Menstrual contamination.

What is bilirubin derived from?

Hemoglobin breakdown.

Identify the principle behind the bilirubin test pad.

Diazo reaction.

What reagent is used in the bilirubin pad?

Diazonium salt.

True or False: Positive bilirubin gives a tan or pink color.

True.

Fill in the blank: A positive Ictotest confirms the presence of ________.

Bilirubin.

Identify the principle of the Ictotest.

Diazo reaction with mat for better sensitivity.

What condition is suggested by bilirubinuria?

Liver disease or biliary obstruction.

True or False: Bilirubin in urine is always pathologic.

True.

Fill in the blank: A false negative bilirubin result can be due to ________.

Ascorbic acid or light exposure.

Identify the product of bacterial metabolism of bilirubin.

Urobilinogen.

What is the normal value of urobilinogen in urine?

True or False: The reagent pad cannot detect absence of urobilinogen.

True.

What reagent is used for urobilinogen testing in Multistix?

p-Dimethylaminobenzaldehyde.

Fill in the blank: The Ehrlich reaction is used to detect ________.

Urobilinogen.

Identify one condition with increased urobilinogen.

Hemolytic disorders.

True or False: Nitrite is formed by gram-positive bacteria.

False.

What is the principle of the nitrite reagent pad?

Greiss reaction.

Fill in the blank: The nitrite pad detects bacteria that reduce ________ to nitrite.

Nitrate.

True or False: A negative nitrite result rules out UTI.

False.

What is required for a positive nitrite result?

Urine retention in the bladder for at least 4 hours.

Identify a cause of false negative nitrite result.

Non-nitrate reducing bacteria or low dietary nitrate.