UA rotation

Question 1

KEY UA FINDINGS associated with nephrotic syndrome

Answer 1

• Marked proteinuria >3.5 g/day
• Hematuria
• Fat droplets, oval fat bodies, fatty casts
• RTEs and casts
• Waxy casts

Question 2

KEY UA FINDINGS associated with acute glomerulonephritis

Answer 2

blood, protein, and RBC casts in urine

Question 3

KEY UA FINDINGS associated with acute pyelonephritis

Answer 3

• Many WBCs, bacteria, increased pH, mild proteinuria, hematuria
• WBC casts

Question 4

KEY UA Findings associated with a bladder infection/cystitis

Answer 4

Many WBCs, bacteria, increased pH, mild proteinuria, hematuria

Question 5

Bilirubin test principle

Answer 5

This test is based on the coupling of bilirubin with diazotized dichloroaniline in a strongly acid medium.

Question 6

Blood test principle

Answer 6

This test is based on the peroxidase-like activity of hemoglobin, which catalyzes the reaction of diisopropylbenzene dihydroperoxide and 3,3’,5,5’-tetramethylbenzidine.

Question 7

Glucose test principle

Answer 7

This test is based on a double sequential enzyme reaction. One enzyme, glucose oxidase, catalyzes the formation of gluconic acid and hydrogen peroxide from the oxidation of glucose. A second enzyme, peroxidase, catalyzes the oxidative coupling of 4-amino-antipyrine and 4-methylcatechol by hydrogen peroxide.

Question 8

Ketone test principle

Answer 8

This test is based on the reaction of nitroprusside with acetoacetic acid.

Question 9

Leukocytes test principle

Answer 9

Granulocytic leukocytes contain esterases that catalyze the hydrolysis of the derivatized pyrrole amino acid ester to liberate 3-hydroxy-5-phenyl pyrrole. This pyrrole then reacts with a diazonium salt.

Question 10

Nitrite test principle

Answer 10

This test depends upon the conversion of nitrate (derived from the diet) to nitrite by the action of Gram negative bacteria in the urine. At the acid pH of the test area, nitrite in the urine reacts with ρ-arsanilic acid to form a diazonium compound. This diazonium compound in turn couples with 1,2,3,4-tetrahydrobenzo(h)quinolin-3-ol.

Question 11

pH test principle

Answer 11

This test is based on a double indicator principle that gives a broad range of colors covering the entire urinary pH range.

Question 12

protein test principle

Answer 12

This test is based on the protein-error-of-indicators principle. At a constant pH, the presence of protein causes a change in the color of the indicator.

Question 13

Urobilinogen test principle

Answer 13

This test is based on the Ehrlich reaction in which ρ-diethylaminobenzaldehyde in conjunction with a color enhancer reacts with urobilinogen in a strongly acid medium.

Question 14

Color principle

Answer 14

This non-reactive white pad absorbs the sample to detect urine color.

Question 15

Criteria for microscopy/reflex

Answer 15

Protein: ≥ 2+ – 4+
Blood: ≥ 2+ – 3+
Nitrite: Positive
Leukocyte: ≥ 2+ – 3+

Question 16

Protein limitation

Answer 16

False positive results may be obtained with highly buffered or alkaline urine

Question 17

Blood limitation

Answer 17

Captopril (Capoten) and other compounds containing sulfhydryl groups may reduce the sensitivity. Certain oxidizing contaminants, such as hypochlorite, may produce alse positive results. Microbial peroxidase associated with urinary tract infection may cause a false positive reaction.

Question 18

Leukocyte limitation

Answer 18

Elevated glucose concentrations (≥ 3 g/dL or 160 mmol/L) may cause decreased test results. The presence of cephalexin (Keflex), cephalothin (Keflin), or high concentrations of oxalic acid may also cause decreased test results. Tetracycline may cause decreased reactivity, and high levels of the drug may cause a false negative reaction. Positive results may occasionally be due to contamination of the specimen by vaginal discharge

Question 19

Nitrite limitation

Answer 19

A negative result does not rule out significant bacteriuria. False negative results may occur with shortened bladder incubation of the urine, absence of dietary nitrate, or the presence of nonreductive pathological microbes. The presence of colored precipitates may cause a false positive result.

Question 20

Glucose limitation

Answer 20

Urine samples with a pH of 9.0 and greater will cause falsely elevated glucose results.

Question 21

Ketone limitation

Answer 21

False Trace results may occur with highly pigmented urine specimens or those containing large amounts of levodopa metabolites. Compounds that contain sulfhydryl groups, such as mesna (2-mercaptoethane sulfonic acid) and captopril, may cause false positive results or an atypical color reaction.

Question 22

pH limitation

Answer 22

Bacterial growth by certain organisms in a specimen may cause a marked alkaline shift (pH > 8.0), usually because of urea conversion to ammonia.

Question 23

Bilirubin limitation

Answer 23

Indican (indoxyl sulfate) can produce a yellow-orange to red color response that may interfere with the interpretation of a negative or positive reading. Metabolites of etodolac (Lodine) may cause false positive or atypical results. Atypical colors may indicate the presence of bile pigment abnormalities and the urine specimen should be tested further.

Question 24

Urobilinogen limitation

Answer 24

The reagent area may react with interfering substances known to react with Ehrlich’s reagent, such as ρ-aminosalicylic acid and sulfonamides. False negative results may be obtained if formalin is present. The test is not a reliable method for the detection of porphobilinogen.

Question 25

Color limitation

Answer 25

Because of the inherent differences between the perception of the human eye and the optical system of the instrument, there may be differences between the color that is perceived visually and that is reported by the instrument, especially when there are low levels of a color present

Question 26

UF-1000 test principle

Answer 26

Flow cytometry measurement of forward scattered light (FSC), side scattered light (SSC) and fluorescence (Fl).

Question 27

Novus minimum volume

Answer 27

2 mL

Question 28

UF-1000 minimum volume

Answer 28

1ml for manual mode and 4ml for auto mode

Question 29

Novus AND UF-1000 minimum volume

Answer 29

5 mL