M3. Chemical Phase of Urinalysis

• “Run-over” effect happens when urine reagent strip is not blotted
• Leaching: happens when prolonged dipping
• Dip reagent strip for less than 1 second
• Reagent strip is stored below 30°C (but never refrigerated) specifically 9 to 29 °C
• Analyses urine and gives a result after 2 minutes. Automates the urine testing process, improving efficiency and accuracy compared to manual methods


  Urilyzer 100 Pro
• Random Urine pH is 4.5 to 8.0
• First morning Urine pH is 5 to 6
• pH of unpreserved urine is greater than or equal to 9
• Enumerate the pH Clinical Significance:

  1. Acidosis and Alkalosis
  2. Renal calculi formation
  3. Identification of crystals
  4. Management of UTI
• Diarrhea causes a loss of Bicarbonate (making it acidic)
• Vomiting causes a loss of Gastric acid (making it basic)
• The primary determinant of pH is diet
• Cranberry juice is good for patients with UTI because it has Quinic and Hippuric acid which are antibacterial
• Starvation, Dehydration, High-protein diet, and cranberry juice cause Acid Urine
• Hyperventilation, Vegetarian diet, and Old Specimens cause Alkaline urine
• No known substances interfere with urinary pH measurements performed by reagent strips
• Reagent Strip Principle: DOUBLE INDICATOR SYSTEM
• methyl red and bromthymol blue are the 2 indicators of the double indicator system and measures between 5 to 9
• PROTEINURIA

  • Albumin is excreted at 100 mg/24 hrs
• Albumin is the major serum protein found in the urine; only protein detected by reagent strip
• Other proteins present in the urine

  • Tamm-Horsfall protein
  • Serum and tubular macroglobulin 
  • Proteins from prostatic/vaginal secretions
• Types of Proteinuria

  • Minimal proteinuria (<1 g/day) 
  • Moderate proteinuria (1 to 3 or 4 g/day) 
  • Marked proteinuria (> 3 or 4 g/day)
• Tamm-Horsfall protein

  • Aka Uromodulin
  • produced by renal tubular epithelial cells
  • seen in patients with acute kidney injury and chronic kidney disease
• infection and inflammation (Liver, lungs, heart)?

  Pre-renal
• glomerular and tubular damage?

  Renal
• lower urinary tracts (organs after kidney are affected) ?

  Post-renal
• Physiological increase (protein) are due to fever, increase physical activity, posture
• PRE-RENAL/OVERFLOW PROTEINURIA

  • Intravascular hemolysis, hemoglobin  Muscle injury, myoglobin
  • Infection & inflammation, APRs (Acute Phase Reactants)
  • Multiple myeloma, Bence-Jones protein
• composition of Bence Jones Protein?

  Identical kappa and lambda
• protein found in multiple myeloma, chronic leukemia and bone tumor?

  Bence Jones
• BENCE JONES PROTEIN

  solubility characteristics: coagulates at 40 to 60 degrees and dissolves at 100 degrees Celsius
• Screening of bence jones proteins: Bradshaw, Toluene sulfonic acid and heating
• • Confirmatory of bence jones protein: electrophoresis
• RENAL PROTEINURIA - TRUE RENAL DISEASE

  • Glomerular proteinuria
  • Orthostatic/cadet/postural proteinuria
  • Pre-eclampsia, hypertension  
  • Dehydration, exercise
• MICROALBUMINURIA

  • For proteins that cannot be detected using reagent strip
  • Presence: increased risk of cardiovascular disease
• • Diabetic nephropathy
  • Indicator: microalbuminuria
• Micral Test

  • Principle: Enzyme immunoassay
  • Result: 60 sec / Reagent pad color Red
• POST-RENAL PROTEINURIA

  • UTI, injury, and trauma
  • Menstrual contamination
  • Vaginal/prostatic secretions
• Reagent Strip Principle of PROTEIN: PROTEIN ERROR OF INDICATORS
• SULFOSALICYLIC ACID PRECIPITATION TEST

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