UA rotation Flashcards
KEY UA FINDINGS associated with nephrotic syndrome
- Marked proteinuria >3.5 g/day
- Hematuria
- Fat droplets, oval fat bodies, fatty casts
- RTEs and casts
- Waxy casts
KEY UA FINDINGS associated with acute glomerulonephritis
blood, protein, and RBC casts in urine
KEY UA FINDINGS associated with acute pyelonephritis
- Many WBCs, bacteria, increased pH, mild proteinuria, hematuria
- WBC casts
KEY UA Findings associated with a bladder infection/cystitis
Many WBCs, bacteria, increased pH, mild proteinuria, hematuria
Bilirubin test principle
This test is based on the coupling of bilirubin with diazotized dichloroaniline in a strongly acid medium.
Blood test principle
This test is based on the peroxidase-like activity of hemoglobin, which catalyzes the reaction of diisopropylbenzene dihydroperoxide and 3,3’,5,5’-tetramethylbenzidine.
Glucose test principle
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.
Ketone test principle
This test is based on the reaction of nitroprusside with acetoacetic acid.
Leukocytes test principle
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.
Nitrite test principle
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.
pH test principle
This test is based on a double indicator principle that gives a broad range of colors covering the entire urinary pH range.
protein test principle
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.
Urobilinogen test principle
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.
Color principle
This non-reactive white pad absorbs the sample to detect urine color.
Criteria for microscopy/reflex
Protein: ≥ 2+ – 4+
Blood: ≥ 2+ – 3+
Nitrite: Positive
Leukocyte: ≥ 2+ – 3+
Protein limitation
False positive results may be obtained with highly buffered or alkaline urine
Blood limitation
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.
Leukocyte limitation
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
Nitrite limitation
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.
Glucose limitation
Urine samples with a pH of 9.0 and greater will cause falsely elevated glucose results.
Ketone limitation
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.
pH limitation
Bacterial growth by certain organisms in a specimen may cause a marked alkaline shift (pH > 8.0), usually because of urea conversion to ammonia.
Bilirubin limitation
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.
Urobilinogen limitation
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.
Color limitation
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
UF-1000 test principle
Flow cytometry measurement of forward scattered light (FSC), side scattered light (SSC) and fluorescence (Fl).
Novus minimum volume
2 mL
UF-1000 minimum volume
1ml for manual mode and 4ml for auto mode
Novus AND UF-1000 minimum volume
5 mL
