1 Flashcards
Principle:Double indicator system
Parameter: pH
Correlations of pH
✓ Nitrite
✓ Leukocytes
✓ Microscopic
1.Increase ph 7
2. Decrease ph 7
1.AMORPHOUS phosphate
2.AMORPHOUS URATES
Causes Acid urine
✓ Emphysema
✓ Diabetes mellitus
✓ Starvation
✓ Dehydration
✓ Diarrhea
✓ Presence of acid-producing
bacteria (Escherichia coli)
✓ High-protein diet
✓ Cranberry juice
✓ Medications (methenamine
mandelate [Mandelamine],
fosfomycin tromethamine
[Monurol])
IT CAUSES
✓ Hyperventilation
✓ Vomiting
✓ Renal tubular acidosis
✓ Presence of urease producing
bacteria
✓ Vegetarian diet
✓ Old specimen
“HPORVV”
Alkaline urine
PROTEIN principle
Principle: protein error of indicator
PROTEIN reagent
Multistix:
Chemstrip:
Multistix: Tetrabromophenol blue
✓ Chemstrip: 3’,3’’,5’,5’’-tetrachlorophenol 3,4,5,6-
tetrabromosulfophthalein
Sensitivity of protein
Multistix: ________________________________
✓ Chemstrip: ____________________
Multistix: 15-30 g/dL albumin
✓ Chemstrip: 6mg/dL albumin more sensitive
• Highly buffered interference alkaline urine
• Pigmented specimens, phenazopyridine
• Quaternary ammonium compounds
(detergents)
• Antiseptics, chlorhexidine
• Loss of buffer from prolonged exposure of the
strip to the specimen reagent
• High specific gravity
False positive result in protein
False neg in protein
• Proteins other than albumin
• Microalbuminuria
Correlation in protein
BLOOD
nitrite
LEUKOCYTES
microscopic
Glucose principle
Double sequential enzymatic reaction
Multistix and chemstrip of glucose
Multistix: potassium iodide (green to
brown)
▪ Chemstrip: tetramethylbenzidine (yellow
to green
Glucose + O2 air______ _> Gluconic acid + H202 hydorgen peroxide. What is the first catalyst in glucose parameter
Glucose oxidase
Protein negative result
Yellow
Protein positive result?
Blue green
Protein concentration increase result to?
GREEN BLUE
H2O2 + chromogen________ -> oxidized colored chromogen +H2O
What is the 2nd catalyst in glucose
Peroxidase
Is used if the px is allergic to iodine
Chlorhexidine aseptics
Regents in glucose
Multistix
Chemstrip
Multistix: Glucose oxidase, Peroxidase,
Potassium iodide
✓ Chemstrip: Glucose oxidase, Peroxidase,
Tetramethylbenzidine
Sensitivity of glycose
Multistix:
Chemstrip: _______
Multistix: 75-125mg/dl
✓ Chemstrip: 40 mg
Contamination by oxidizing agents and detergents
False positive in glucose
False negative in glucose is due to?
🙁High levels of ascorbic acid
• High levels of ketones
• High specific gravity
• Low temperatures
• Improperly preserved specimens
Correlations of glucose
Ketones
Protein
Reagent strip reaction of glucose
Copper reduction test
The only non reducing sugar
Sucrose
method by impregnating the testing area with a mixture of glucose oxidase, peroxidase, chromogen, and buffer to produce a double sequential enzyme reaction
Glucose oxidase
• Relies on the ability of glucose and other substances to reduce copper sulfate to cuprous oxide in the presence of alkali and heat
Copper reduction test [clinitest]
Glucose blue to green reaction is called?
“PASS-THROUGH” phenomenon
B-g-red-blue
Will oxidize the reducing substance due to heat and alkali
CuSO4 (Cupric Sulfide)
Present in urine
Reducing substance
Cu2O (Cuprous Oxide) +
Oxidized Substance →
Color (Blue/Green →
Orange/Red)
Principle of ketones
Niropusside reaction
Produce a purple color
Sodium nitroprusside nitroferricyanide
Use ACETEST TABLETS
Ketones
Acetoacetate (& acetone) + Sodium Nitroprusside + Glycine in alkaline will produce a color of? In ketones
Purple
Reagents in ketones
Sodium nitroprusside
Glycine (Chemstrip)
Ketones sensitivity
Multistix
Chemstrip
Multistix: 5-10 acetoacetic acid
Chemstrip: 9mg/dl acetoacetic acid;70 mg/dl acetone
✓ False Positive in ketones
✓ False Positive
• Phthalein dyes
• Highly pigmented red urine
• Levodopa
• Medications containing free sulfhydryl groups
False neg in ketones
Improperly preserved specimens
Ketones correlations
Glucose
Principle of blood
Pseudoperoxidase activity of hemoglobin
Reagent of blood
Mutistix
Chemstrip
Multistix: Diisopropylbenzene dihydroperoxide
and 3,3’,5,5’- tetramethylbenzidine
Chemstrip: dimethyldihydroperoxyhexane and
tetramethylbenzidine
Chromogen of blood
tetramethylbenzidine
Blood reagent
Multistix
Chemstrip
Multistix: Diisopropylbenzene dihydroperoxide
and 3,3’,5,5’- tetramethylbenzidine
✓ Chemstrip: dimethyldihydroperoxyhexane and
tetramethylbenzidi
False-positive result in blood
• Strong oxidizing agents
• Bacterial peroxidases
• Menstrual contamination
False neg in blood
High specific gravity/crenated cells
• Formalin
• Captopril
• High concentrations of nitrite
• Ascorbic acid greater than 25 mg/dL
• Unmixed specimens
Corellations in blood
Protein
Microscopic
Principle of BILIRUBIN
diazo
uses ICTOTEST TABLETS
Bilirubin
Reagents of bilirubin
multistiz
Chemstrip
✓ Multistix: 2,4-dichloroaniline diazonium salt
✓ Chemstrip: 2,6-dichlorobenzenediazonium salt
Reagents of bilirubin
multistiz
Chemstrip
✓ Multistix: 2,4-dichloroaniline diazonium salt
✓ Chemstrip: 2,6-dichlorobenzenediazonium salt
FALSE positive result in bilirubin is caused by?
- Highly pigmented urines,
- phenazopyridine
- Indican (intestinal disorders)
- Metabolites of Lodine
False-negative in bilirubin
- Specimen exposure to light
- Ascorbic acid greater than 25 mg/dL
*High concentrations of nitrite
Correlation of bilirubin
✓ Urobilinogen
UROBILINOGEN principle
Erlich/ diazo reaction
p-dimethylaminobenzaldehyde will produce what color?
light to dark pink
4-methoxybenzenediazoniumtetrafluoroborate will produce what color in urobilinogen
white to pink
UROBILINOGEN negative result will produce what color?
white
Reagent in urobilinogen
Multistix:
Chemstrip:
Multistix: p-dimethylaminobenzaldehyde
✓ Chemstrip: 4-methoxybenzenediazonium-
✓ tetrafluoroborate
False positive in urobilinogen
(MULTISTIX)
Porphobilinogen
* Indican
* p-aminosalicylic acid
* Sulfonamides
* Methyldopa
* Procaine
* Chlorpromazine
* Highly pigmented urine
False negative result in urobilinogen
(MULTISTIX)
Old specimens
* Preservation in formalin
Chemstrip:
✓ False-positive in urobilinogen
- Highly pigmented urine
Chemstrip:
✓ False-positive in urobilinogen
- Highly pigmented urine
✓ False-negative chemstrip in urobilinogen
- Old specimens
- Preservation in formalin
- High concentrations of nitrite
nitrite principle
greiss reaction
First reaction in nitrite
p-arsanilic acid (or sulfanilamide) NO2->Diazonium Salt (Nitrite
Diazonium Salt + tetrahydrobenzoquinolin->Pink Azodye
second reaaction in nitrite
Reagents in nitrite
Multistix: p-arsanilic acid, Tetrahydrobenzo(h)-
quinolin-3-ol
Chemstrip: Sulfanilamide,
hydroxytetrahydrobenzoquinoline