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Urochrome - yellow color of urine
- Thudichum (1864) Uroerythrin Attaches to the urates, producing a pink color Urobilin Constituent to urobilinogen, imparts an orange-brown color to urine that is not fresh DARK YELLOW/AMBER/ORANGE Bilirubin Yellow foam appears when the specimen is shaken May contain hepatitis virus Protein White foam indicates an increased concentration Biliverdin Photo-oxidation of bilirubin imparts a yellow-green color Phenazopyridine Pyridium or azo-gantrisin compounds to people who have UTI Orange color , produce a yellow foam when shaken RED/PINK/BROWN Acidic Due to the oxidation of hemoglobin to methemoglobin Fresh brown Indicate glomerular bleeding RBCs are present Red and cloudy (Hematuria) hemoglobin and myoglobin Red and clear Hemoglobinuria From the in vivo breakdown of RBCs is accompanied by red plasma Myoglobin Breakdown of skeletal muscle; reddish-brown; clear plasma Porphyrins Porphobilinogen to porphyrins having the color of port wine Nonpathogenic causes
- Menstrual contamination
- Ingestion of highly pigmented foods
- Medications Alkaline urine beets Acidic urine Blackberries BROWN/BLACK Melanin Oxidation product of melanogen Homogentisic acid Metabolite of phenylalanine, black color to alkaline urine Alkaptonuria Persons with the inborn-error of metabolism BLUE/GREEN Pseudomonas urinary tract infection resulting in increased urinary indican Clorets Breath deodorizers; Green Klebsiella or Providencia Purple; May occur in catheter bags and is caused by indican in the urine or a bacterial infection CLARITY Clear No visible particulates, transparent Hazy Few particulates, print easily seen through urine Cloudy Many particulates, print blurred through urine Turbid Print cannot be seen through urine Milky May precipitate or be clotted CAUSE OF URINE TURBIDITY PATHOLOGIC NONPATHOLOGIC Non-squamous RBC WBC Bacteria epithelial cell Yeast Abnormal crystals Lymph fluid Lipids Squamous epithelial cells Mucus Amorphous phosphates, carbonates, urates Semen, spermatozoa Fecal contamination Radiographic contrast media Talcum powder Vaginal creams SPECIFIC GRAVITY
- Evaluation of the kidney’s reabsorption ability can be performed by measuring the specific gravity of a specimen
- Measure of the density of the dissolved chemicals in the specimen TERM SPECIFIC GRAVITY Isosthenuric 1. Hyposthenuric Below 1. Hypersthenuric Above 1. Normal range for random specimen
Sample is not urine Lower than 1. Most random specimen 1.015-1. Radiographic contrast media
DIRECT METHODS
URINOMETER
Principle Buoyancy ; Urinometer will float higher in urine and in water, because urine is denser Purpose A hydrometer that is calibrated to measure specific gravity of urine at a specific temperature, usually 20°C How to use (^) • 15 mL of mixed urine is placed in a glass cylinder
- Any foam or bubbles must be removed Correction For every 3°C above/below the urinometer calibration, 0. must be added/subtracted from reading HARMONIC OSCILLATION DENSITOMETRY Principle Sound wave entering a solution change in proportion to the density of the solution Purpose Shifts in harmonic oscillation are measured and relative density is calculated How to use
- 15 mL of mixed urine is placed in a glass cylinder
- Any foam or bubbles must be removed Correction For every 3°C above/below the urinometer calibration, 0.001 must be added/subtracted from reading INDIRECT METHODS REFRACTOMETER Principle Refractive index Purpose Determines the concentration of dissolved particles in a specimen by measuring the refractive index How to use A drop of urine is placed on the prism Calibration Distilled water that should read 1. 5% NaCl 1.022 ± 0. 9% sucrose
Correction Protein, 0.003 must be subtracted Glucose, 0.004 must be subtracted > 1.040 Abnormally high result ; recently undergone an intravenous pyelogram
REAGENT STRIP
Principle pKa changes of polyelectrolyte by ions present Bromthymol blue Indicator change in pH Blue Specific gravity 1.000 [alkaline] Green to yellow Specific gravity 1.030 [acid] OSMOLALITY Principle Changes in colligative properties by particle number ODOR Aromatic, faintly Normal urine Ammoniacal Old urine- improperly stored Pungent, fetid Urinary tract infection Sweet, fruity Ketone production due to: a. Diabetes mellitus b. Starvation, dieting, malnutrition c. Strenuous exercise d. Vomiting, diarrhea Mousy Phenylketonuria Maple syrup Maple syrup urine disease Rancid Tyrosinemia Rotting/old fish Trimethylaminuria Cabbage, hops Methionine malabsorption Sweaty feet Isovaleric acidemia Distinctive Ingested substances; asparagus, garlic, onions Menthol-like Phenol containing medications Bleach Adulteration of the specimen or container contamination
a home remedy for minor bladder infections pH > 8.5 Associated with an improperly preserved specimen Metabolized to produce an acidic urine Mandelamine Methenamine mandelate Monurol Fosfomycin tromethamine Kidneys regulate the acid-base o The secretion of hydrogen in the form of ammonium ions hydrogen phosphate, and weak organic acids o By the reabsorption of bicarbonate from the filtrate in the convoluted tubules Clinical Significance Aid in determining the existence of systemic acid– base disorders of metabolic or respiratory origin and in the management of urinary conditions
- Respiratory or metabolic alkalosis
- Treatment of urinary tract infections
- Precipitation/identification of crystals
- Determination of unsatisfactory specimens Acid Urine Alkaline Urine - Cranberry juice - Presence of acid- producing bacteria (E. coli) - Diabetes mellitus - Medications - Diarrhea - Starvation acidosis - High-protein diet - Emphysema - Dehydration - Hyperventilation - Old specimens - Presence of urease- producing bacteria - Vomiting - Renal tubular - Vegetarian diet If alkaline detergent remains in the container, it can produce a pH > 8. PROTEIN MULTISTIX CHEMSTRIP Tetrabromophenol blue 3’,3’’,5’,5’’-tetrachlorophenol 3,4,5,6- tetrabromosulfophthalein 15 - 30 mg/dL albumin 6 mg/dL albumin PRINCIPLE Protein error of indicators Normal value < 10 mg/dL or 100 mg/24 hours Clinical proteinuria > 30 mg/dL (300 mg/L) Renal disease Most indicative of Proteinuria Associated with early renal disease Albumin Major serum protein Uromodulin Uromucoid Tamm-Horsfall protein produced in the distal convoluted tube and forms all types of casts Urokinase Fibrinolytic enzyme secreted by tubular cells Prerenal Proteinuria
- Reagent strips detect primarily albumin, prerenal proteinuria is usually not discovered in a routine urinalysis Acute Phase Reactants Septicemia, severe infection or inflammation Hemoglobin After hemolytic episode, intravascular hemolysis Myoglobin Following muscle injury Bhence-Jones Proteins Immunoglobulin paraptroteins produced in Multiple Myeloma and Macroglobulinemia Renal Proteinuria
- Associated with TRUE RENAL DISEASE
- Has a pattern Glomerular Proteinuria Glomerular filtration barrier is blocked Pre-eclamptic state Occurs during the latter months of pregnancy Microalbuminuria Persons with type 1 and 2 diabetes mellitus can be predicted by Orthostatic (Postural) Proteinuria higher urinary protein caused by being in a vertical position 1st : morning (-) 2nd : vertical position for hours (+) Tubular Proteinuria Increased albumin due to the cessation of the reabsorption of normally filtered albumin Fanconi syndrome Postrenal Proteinuria
- Presence of blood as the result of injury or menstrual contamination contributes protein, as does the presence of prostatic fluid and large amounts of spermatozoa
Sulfosalicylic Acid Precipitation Test
- Cold precipitation test that reacts equally with all forms of protein GRADE TURBIDITY PROTEIN RANGE (MG/DL) Negative No increase in turbidity < Trace Noticeable turbidity 6 - 30 1+ Distinct turbidity with no granulation
2+ Turbidity with granulation with no flocculation
3+ Turbidity with granulation and flocculation
4+ Clumps of protein > ALBUMIN:CREATININE RATIO Micral-Test PRINCIPLE Enzyme immunoassay Reagents Gold-labeled antibody B-galactosidase Chlorophenol red galactoside Sensitivity 0 to 10 mg/dL False (-) Dilute urine ImmunoDip PRINCIPLE Immunochromographics Reagents Antibody-coated Blue latex particles Sensitivity 1.2 to 8.0 mg/dL False (-) Dilute urine Clinitest Microalbumin Strips/Multistix-Pro PRINCIPLE Sensitive albumin tests related to creatinine concentration to correct for patient hydration Sensitivity Albumin : 10 to 150 mg/L Creatinine : 10 to 300 mg/dL, 0. to 26.5 mmol/L Interference Visibly bloody or abnormally colored urine Creatinine: Cimetidine: False positive
GLUCOSE
MULTISTIX CHEMSTRIP
Glucose oxidase Peroxidase Potassium iodide Glucose oxidase Peroxidase Tetramethylbenzidine 75 - 125 mg/dL 40 md/dL Copper reduction test for glucose PRINCIPLE Double sequential enzyme reaction
Gestational
diabetes
Hyperglycemia that occurs during pregnancy and disappears after delivery Onset 6th month of pregnancy Hyperglycemia and glucosuria Increased glucagon, epinephrine, cortisol, thyroxine, and growth hormone Glycogenesis Primary function of insulin is to convert glucose to glycogen for storage Glycogenolysis Breakdown of glycogen to glucose Glycosuria Occurs in the absence of hyperglycemia when the reabsorption of glucose by the renal tubules is compromised Copper Reduction Test (Clinitest) PRINCIPLE Reduced copper sulfate to cuprous oxide (blue to orange) Reagents Copper sulfate, Sodium carbonate Sodium citrate Sodium hydroxide Sensitivity 200 mg/dL
- Pass through - color produced passes through the orange/red stage and returns to a green- brown color
- Benedict’s principle
- Does NOT provide a confirmatory test for glucose
- Clinitest tablets are very hygroscopic
- Strong blue color : deterioration due to moisture accumulation, as does vigorous tablet fizzing
- Often performed on pediatric specimens from patients up to at least the age of 2 years
- “Inborn error of metabolism” in which lack of the enzyme galactose- 1 - phosphate uridyl transferase
LEUKOCYTE ESTERASE
MULTISTIX CHEMSTRIP
Derivatized pyrrole amino acid ester Diazonium salt Indoxylcarbonic acid ester 5 to 15 WBC/hpf 10 to 25 WBC/hpf PRINCIPLE Hydrolysis of an ester Result Purple azo-dye High power field SPECIFIC GRAVITY MULTISTIX CHEMSTRIP Poly (methyl vinyl ether/maleic anhydride) Bromthymol blue Ethylene glycol diaminoethyl ether tetraacetic acid Bromthymol blue 1.000 to 1. PRINCIPLE Change in pKa of a polyelectrolyte in an alkaline medium ASCORBIC ACID PRINCIPLE Reduce dye impregnated in the reagent wherein two reduced dye causes a distinct color change from BLUE TO ORANGE Result 7 – 20 mg/dL Manufacturers 1. vChem (Iris Diagnostics
- Urispec GP (Henry Schein Inc.) BBLNG!
