Urine Glucose Reagent Strip Parameters Quiz

Urine Glucose Testing

• Reagent strips are used to detect glucose in urine, utilizing a double sequential enzymatic reaction involving two enzymes: glucose oxidase and peroxidase.
• The reagent strip contains a mixture of glucose oxidase, peroxidase, chromogen (indicator), and buffer.
• The enzyme reaction produces a color change, which is compared to a color chart to determine the glucose level.

Quality Control for Reagent Strips

• Manual quality control methods can be used when questionable results are obtained or when a new bottle is opened.
• Precautions for using reagent strips include:
  • Mixing the urine specimen thoroughly
  • Not allowing the strip to remain in the urine for extended periods
  • Blotting the edge of the strip after dripping to prevent run-over
  • Comparing color reactions with the color charts horizontally
  • Following specific timing for each pad
  • Using a good light source
  • Not interchanging reagents strips and color charts from different manufacturers
  • Allowing refrigerated specimens to return to room temperature before using reagent strips
  • Protecting reagent strips from deterioration caused by moisture, volatile chemicals, heat, and light
  • Storing reagent strips tightly closed at room temperature below 30°C and not refrigerated
  • Not using past the expiration date

Reaction Interferences

• False positive results can occur due to:
  • Hydrogen peroxide
  • Urine container contaminated with detergents
• False negative results can occur due to:
  • Ascorbic acid
  • High level of ketones
  • High specific gravity of urine
  • Low temperature
  • Prolonged standing of urine

Copper Reduction Tests for Glucose

• The copper reduction test relies on the ability of glucose and other reducing substances to reduce copper sulfate to cuprous oxide in the presence of alkali and heat.
• Tests that utilize this principle include:
  • Benedict's Test
  • Clinitest Tablet

Urine Glucose Clinical Significance

• Hyperglycemia is associated with:
  • Diabetes Mellitus
  • Impaired function of insulin
  • Pancreatitis
  • Decreased levels of insulin
  • Pancreatic cancer
  • Increased glucagon and somatostatin
  • Acromegaly
  • Increased growth hormone
  • Increased cortisol
  • Increased epinephrine
  • During pregnancy
  • Cushing Syndrome
  • Pheochromocytoma
  • CNS damage
  • Stress
  • Gestational Diabetes
• Renal associations (defects in kidney's tubular reabsorption) include:
  • Fanconi Syndrome
  • Tubular Disorders
  • Advanced Renal Disease
  • Osteomalacia
  • Vitamin D deficit (softening of bone)

Chemical Examination of Urine

• Chemical examination of urine validates the physical aspect of urine analysis.
• Reagent strips are a sensitive and rapid procedure for chemical screening of urine.
• The reagent strip technique involves:
  • Dipping the reagent strip briefly into a well-mixed urine at room temperature
  • Removing excess urine by touching the edge of the strip to the container upon withdrawal
  • Blotting the edge of the strip into an absorbent pad
  • Waiting for the specified amount of time
  • Comparing the color reaction of each pad to the manufacturer's color chart