CHEMICAL EXAMINATION OF URINE Flashcards by Janus Palermo

Urine strip parameter(s) with 30 secs reading time

Glucose
Bilirubin

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Urine strip parameter(s) with 40 secs reading time

Ketones

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Urine strip parameter(s) with 45 secs reading time

Specific gravity

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Urine strip parameter(s) with 60 secs reading time

Protein
pH
Blood
Urobilinogen
Nitrite

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Urine strip parameter(s) with 120 secs reading time

Leukocyte esterase

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Principle of Glucose urine strip

Double sequential enzyme reaction

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Principle of Bilirubin urine strip

Diazo reaction

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Principle of Ketones urine strip

Sodium nitroprusside reaction

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Principle of Specific Gravity Urine Strip

pKa change of a polyelectrolytes

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Principle of Protein urine strip

Protein error of indicators

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Principle of pH urine strip

Double indicator system

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Principle of Blood urine strip

Pseudoperoxidase activity of hemoglobin

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Principle of urobilinogen urine strip

Ehrlich reaction

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Principle of Nitrite urine strip

Greiss reaction

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Principle of Leukocytes urine strip

Leukocyte esterase

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Reagent Strip technique (true or false)

Dip the reagent strip briefly (no longer than 1 second) into a centrifuged urine specimen at RT.

false - dip the reagent strip into a will-mixed UNCENTRIFUGED urine specimen

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Reagent Strip technique (true or false)

Remove excess urine by touching the edge of the strip to the container as the strip is withdrawn

True

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Reagent Strip technique (true or false)

Blot the underside of the strip on a disposable absorbent pad

False - Blot the EDGE OF THE STRIP on a disposable absorbent pad

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Reagent Strip technique (true or false)

Hold the strip vertically, and compare the color reaction of the strip pads to the manufacturer’s color chart in good lighting

False - Hold the strip HORIZONTALLY

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true or false

Store without desiccant in an opaque, tightly closed container

False - Store WITH DESICCANT in an opaque, tightly closed container

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true or false

Store below 30C (room temperature); do not freeze

True

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Principle of automated reagent strip readers

Reflectance photometry

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A measure of the amount of dissolved substances in a solution; Density of solution compared with density of similar volume of distilled water at a similar temperature

Specific Gravity

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Reference ranges of specific gravity:

Random urine: __________
1st morning: __________
24-hour urine: _________

Random urine: 1.003 to 1.035
1st morning: >1.020
24-hour urine: 1.016 - 1.022

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if S.G. is <1.003:

Not a urine n(except in D.I)

if S.G. is >1.040

Radiographic dye present (if refractometer is used)

S.G of: Isosthenuria: Hyposthenuria: Hypersthenuria:

Isosthenuria: = 1.010 Hyposthenuria: < 1.010 Hypersthenuria: > 1.010

Calibration temperature of Urinometry (urinometer)

20C

______ for every 3C that the specimen temperature is below the calibration temp.

- 0.001 for every 3C that the specimen temp. is below the calibration temp.

______ for every 3C that the specimen temperature is above the calibration temp.

+ 0.001 for every 3C that the specimen temperature is above the calibration temp.

Correction for glucose and protein: 1 g/dL Glucose = __________ 1g/dL Protein = _________

1 g/dL Glucose = -0.004 1g/dL Protein = -0.003

Urine volume required for urinometer:

10 - 15 mL

Principle or device for specific gravity measurement that doesn't need temperature correction; requires correction for glucose and protein.

Refractometry (Refractometer, Rf/ TS (total solids) meter)

Calibration for refractometer: Distilled/deionized H2O =

S.G. 1.000

Calibration for refractometer: 3% NaCl:

1.015 +/- 0.001

Calibration for refractometer: 5% NaC:

1.022 +/- 0.001

Calibration for refractometer: 7% NaCl:

1.035 +/- 0.001

Calibration for refractometer: 9% Sucrose

1.034 +/- 0.001

Sample problem: (URINOMETRY) Urine S.G. reading by urinometer is 1.025 Urine temperature is 26C Urinometer calibration temp. is 20C what is the corrected SG?

1.027

Sample problem: (REFRACTOMETRY) Urine S.G. reading by refractometer is 1.025 with 2 g/dL glucose and 2 g/dL protein Temperature: 37C what is the corrected SG?

1.011

Reagent for the rgt. strip reaction for specific gravity

bromthymol blue (multistix & chemstrip)

Obsolete method; based on frequency of soundwave entering a solution. changes in proportion to the density of the solution.

Harmonic oscillation densitometry (H.O.D)

Example of H.O.D

Yellow IRIS (International Remote Imaging System)

Urine volume required for IRIS diagnostics

6 mL urine volume

how much urine volume from the 6 mL is required for the IRIS mass Gravity meter?

2 mL (of 6mL)

how much volume from the 6 mL is required for IRIS Slideless microscope?

4 mL (of 6 mL)

Acidity refers to the "_______" of a solution, whereas alkalinity refers to its "_______"

Acidity: sourness Alkalinity: bitterness

Normal urine pH: Random urine: 1st morning:

Random urine: 4.5 - 8.0 1st morning: 5.0 - 6.0

When urine pH is >9.0:

unpreserved urine

occurs after meals due to the withdrawal of H+ ions for the purpose of secretion of HCl.

Alkaline tide

Causes of acid urine:

1. Diabetes Mellitus (high ketone bodies) 2. Starvation (high ketone bodies) 3. High protein diet 4. Cranberry juice (quinic acid--.Hippuric acid)

Causes of alkaline urine:

1. Renal tubular acidosis 2. Vegetarian diet 3. After meal (alkaline tide) 4. Vomiting

Reagent for the rgt. strip reaction for pH

Methyl red bromthymol blue

interferences of reagent strip reaction for pH

No known interference Runover from adjacent pads, old specimens

The parameter that is the most indicative of renal disease; produces white foam in urine when shaken

Protein

Normal urinary protein:

<10 mg/dL or <100 mg/day (Strasinger) <150 mg/day (Henry)

Proteins in normal urine consist of ____ albumin and ____ globulins

1/3 albumin 2/3 globulins

Most abundant protein in normal urine

Tamm-Horsfall protein (Uromodulin)

Caused by conditions that affect the plasma prior to its reaching the kidney

Pre-renal (before) or Overflow proteinuria

conditions that can cause pre-renal proteinuria:

1. Intravascular hemolysis = hemoglobin 2. Muscle injury = myoglobin 3. Severe infection & inflammation = increased APRs 4. Multiple myeloma

Protein present in urine in patients with multiple myeloma

Bence Jones Proteins

BJP in urine precipitates at _____ C (cloudyt) & dissolves at ____ C (clear)

BJP precipitates at 40-60C & dissolves at 100C

Normal Albumin Excretion Rate:

0-20 ug/min

Microalbuminuria AER:

20-200 ug/min or 30-300 ug/min/24 hours

Clinical albuminuria AER:

>200 ug/min

Onset of renal complications can be first be predicted by detection of _________.

Microalbuminuria

Test for microalbuminuria; A strip employing antibody-enzyme conjugate that binds albumin

MICRAL TEST

Proteinuria when standing due to increased pressure to renal veins; increased venous pressure causes renal congestion and glomerular changes

Orthostatic/Cadet/Postural/Cyclic proteinuria

Originally discovered in workers exposed to cadmium dust (a heavy metal); Normally filtered albumin can no longer be reabsorbed

Tubular proteinuria

Reagent present for the rgt strip reaction for protein

Citrate buffer at pH 3.0 (multistix & chemstrip) other reminders: "tetra" -tetrabromphenol blue -tetrachlorophenol tetrabromosulfonphthalein

The indicator of protein in the strip reaction is sensitive to _______.

ALBUMIN

A cold precipitation test that reacts equally with all forms of protein

Sulfosalisylic acid precipitation test

SSA test is also known as:

EXTON'S test

procedure in SSA test: 3mL of ___ % SSA + __ mL centrifuged urine ---> 10 mins incubation ---> (+) cloudiness

3% SSA 3 mL centrifuged urine

SSA gradings: Grade: Negative Turbidity: Range (mL/dL) [Strasinger]: Range [Henry]:

Grade: Negative Turbidity: No increase in turbidity Range (mg/dL) [Strasinger]: <6 mg/dL Range [Henry]: = 5 mL/dL

SSA gradings: Grade: Trace Turbidity: Range (mL/dL) [Strasinger]: Range [Henry]:

SSA gradings: Grade: Trace Turbidity: Noticeable or perceptible turbidity Range (mg/dL) [Strasinger]: 6 - 30 mg/dL Range [Henry]: = 20 mg/dL

SSA gradings: Grade: 1+ Turbidity: Range (mL/dL) [Strasinger]: Range [Henry]:

SSA gradings: Grade: 1+ Turbidity: Distinct turbidity with no granulation Range (mL/dL) [Strasinger]: 30 - 100 mg/dL Range [Henry]: = 50 mg/dL

SSA gradings: Grade: 2+ Turbidity: Range (mL/dL) [Strasinger]: Range [Henry]:

SSA gradings: Grade: 2+ Turbidity: Turbidity with granulation but NO flocculation Range (mL/dL) [Strasinger]: 100 - 200 mg/dL Range [Henry]: = 200 mg/dL

SSA gradings: Grade: 3+ Turbidity: Range (mL/dL) [Strasinger]: Range [Henry]:

SSA gradings: Grade: 3+ Turbidity: Turbidity with granulation AND flocculation Range (mL/dL) [Strasinger]: 200 - 400 mg/dL Range [Henry]: = 500 mg/dL

SSA gradings: Grade: 4+ Turbidity: Range (mL/dL) [Strasinger]: Range [Henry]:

SSA gradings: Grade: 4+ Turbidity: Clumps of protein Range (mL/dL) [Strasinger]: >400 mg/dL Range [Henry]: = 1.0 g/dL

A highly buffered alkaline with no albumin present can cause _______ reagent strip False-positive False-negative

False-positive

A highly buffered alkaline with albumin present can cause _________ SSA test False-positive False-negative

False-negative

Chem strip result is negative but positive in SSA. explanation:

- Proteins other than albumin are present - False (+) in SSA = Radiographic contrast media (delayed reaction), Drugs and/or drug metabolites (tolbutamide, penicillins)

S.G. should be considered in evaluating urine protein because a trace protein in a dilute specimen is more significant than in a concentrated specimen true or false

true

Large volumes of urine can produce a negative protein reaction despite significant proteinuria because the protein present is being excessively diluted true or false

true

Parameter that is most frequently tested in urine

Glucose

In Hyperglycemia: Blood glucose: Urine glucose:

Blood glucose - increased Urine glucose - increased/ present

In Renal-associated (Renal Glycosuria) Blood glucose: Urine glucose:

Blood glucose - Normal Urine glucose - increased

Reagent present in rgt strip reaction for glucose:

- Potassium iodide (Multistix) - Tetramethylbenzidine (Chemstrip)

A non-specific test for reducing sugars:

Copper reduction test (Clinitest/Benedict's test)

Reporting (Benedict's test) Clear blue color, blue precipitate may form:

Negative (-)

Reporting (Benedict's test) Bluish-green color

Tr (Trace)

Reporting (Benedict's test) Green color, green or yellow precipitate

Reporting (Benedict's test) Yellow to green color, yellow precipitate

Reporting (Benedict's test) Yellow-orange color, yellow-orange precipitate

Reporting (Benedict's test) Reddish-yellow color, brick red or red precipitate

False-positive Benedict's test causes:

Presence of reducing agents (ascorbic acid, uric acid)

False-negative Benedict's test causes:

Presence of Oxidizing agents (detergents)

A phenomenon that occurs when >2 g/dL sugar is present in clinitest tablet procedure

Pass through phenomenon

to prevent pass-through phenomenon, use _____ gtts urine instead of 5 gtts urine

2 gtts urine

Clinitest sensitivity

200 mg/dL

Summary of glucose oxidase and clinitest reaction: Glucose oxidase: 1+ positive Clinitest: Negative Interpretation: ??

Interpretation: Small amount of glucose is present

Summary of glucose oxidase and clinitest reaction: Glucose oxidase: 4+ positive Clinitest: Negative Interpretation: ??

Interpretation: Possible oxidizing agent interference on reagent strip

Summary of glucose oxidase and clinitest reaction: Glucose oxidase: Negative Clinitest: Positive Interpretation: ??

Interpretation: Non-glucose reducing substance present; possible interfering substance for reagent strip (ex. ascorbic acid)

Result form increased fat metabolism due to inability to metabolize carbohydrate

Ketones

Renal threshold of ketones:

70 mg/dL

Major ketone but not detected in routine reagent strip

Beta-hydroxybutyric acid (BHA)

parent ketone (first ketone body formed)

Acetoacetic acid (AAA) ? Diacetic acid

BHA = ?% AAA = ?% Acetone = ?%

BHA = 78% AAA = 20% Acetone = 2%

Reagent present for the rgt strip reaction for ketones:

Na nitroprusside Nitroferricyanide Glycine (Chemstrip)

Acetone is detected only when _____ is present.

Glycine

Hematuria is described as:

Cloudy red urine

Hemoglobinuria is described as:

Clear red urine

Microscopic analysis in hematuria:

Intact RBCs (>5 RBCs/uL = significant)<

Microscopic analysis in hemoglobinuria:

No RBCs seen note: Heme portion of the hemoglobin is toxic to the renal tubules

Myoglobinuria is described as:

Clear red (red-brown) urine

Myoglobinuria can also be caused by:

Cholesterol-lowering statin medications

Hemoglobin vs Myoglobin In Hemoglobin, plasma color is ______. In Myoglobin, plasma color is ______.

Hemoglobin: Red/pink plasma Myoglobin: Pale yellow plasma

In Blondheim's test (Ammonium sulfate test) for hemoglobin and myoglobin, Hemoglobin = _________. Myoglobin = _________.

Blonheim's test: Hemoglobin = precipitated Myoglobin = not precipitated

Reagent present in rgt strip reaction for blood:

- Tetramethylbenzidine (multistix) - Tetramethylbenzidine (Chemstrip) other reminders: - Diisopropylbenzene dehydroperoxide (multistix) - Dimethyldihydroperoxyhexane (chemstrip)

Bilirubin type that is detected in urine:

Conjugated bilirubin

Physical indication of the presence of bilirubin in urine:

Tea-colored/amber/beer-brown urine with yellow foam

Reagent present for rgt strip reaction for bilirubin:

- 2,4-dichloroaniline diazonium salt (multistix) - 2,6-dichlorobenzene diazonium salt (chemstrip) remember: "dichloro"

color reaction of bilirubin in reagent strip:

(+) Tan or Pink Violet

Bile pigment that resulted from hemoglobin degradation

Urobilinogen

Normal value of urobilinogen in urine:

<1 mg/dL or Ehrlich unit

Specimen for urobilinogen determination:

Afternoon urine (2-4 PM)

Confirmatory test for Bilirubin determination in urine; more sensitive than strip with less interference

ICTOTEST (Tablet)

Reagent present in rgt strip reaction for urobilinogen:

p-dimethylaminobenzaldehyde (PDAB) or Ehrlich reagent) (Multistix) 4-methoxybenzene-diazonium-tetrafluoroborate (specific for UBG)

Causes false-positive results in urobilinogen strip test:

p-aminosalicylic acid

Causes false-negative results in urobilinogen strip test:

Old specimens Formalin (preservative)

A test that differentiates urobilinogen (UBG), porphobilinogen (PBG) and other Ehrlich-reactive compounds (ERC)

Watson-Schwartz Test

Organic solvents used in the Watson-Schwartz test:

Chloroform Butanol

In the Watson-Schwartz test, UBG is:

Soluble in Chloroform and Butanol

In the Watson-Schwartz test, PBG is:

Insoluble in Chloroform and Butanol

In the Watson-Schwartz test, ERC is:

Soluble in Butanol Insoluble in Chloroform

A rapid screening test for porphobilinogen (≥ 2 mg/dL)

HOESCH TEST (Inverse reaction)

Correlations: Blood: Increased UB Urine Bilirubin (CB): Negative Urine urobilinogen: +++ Condition: ??

Extravascular hemolytic disease (Pre-hepatic jaundice)

Correlations: Blood: increased UB/CB Urine bilirubin (CB): +/- Urine urobilinogen: ++ Condition: ??

Liver damage (Hepatic Jaundice)

Correlations: Blood: increased CB Urine bilirubin (CB): +++ Urine urobilinogen: -/decreased (Strip = NORMAL) Condition: ??

Bile duct obstruction (Post-hepatic or obstructive jaundice)

Jaundice due to increased destruction of red blood cells does not produce bilirubinuria true or false

True - because the serum bilirubin is in the unconjugated form and the kidneys cannot excrete it.

Rapid screening test of UTI or bacteria:

Nitrite

Specimen of choice for urine strip for nitrite determination:

4-hour collection or First morning urine (preferred)

Regent present in rgt strip reaction for nitrite:

Remember: "quinoline" - p-arsanilic acid, tetrahydrobenzo(h)-quinolin-3-ol (multistix) - Sulfanilamide, hydroxytetrahydro benzoquinoline (chemstrip)

If the nitrite test area shows a negative reaction, UTI cannot be ruled out true or false

True - Some UTIs are caused by gram (+) cocci & yeasts - they lack nitrate reductase enzyme)

Reagent present in rgt strip reaction for leukocytes:

Remember: "ester" - Derivatized pyrrole amino acid ester, Diazonium salt (multistix) - Indoxylcarbonic acid ester, Diazonium salt (chemstrip)

type of leukocyte without esterase

lymphocyte

the 11th reagent pad of urine strip reaction:

Ascorbic acid (Vitamin C)

Ascorbic acid causes false-negative reactions on:

1. Blood 2. Bilirubin 3. Leukocytes 4. Nitrite 5. Glucose Remember: "BaBy LaNGga" or "BB LNG"

CHEMICAL EXAMINATION OF URINE Flashcards

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