Chemical Examination Of Urine Prt.2 Flashcards
• is a breakdown product of hemoglobin that is formed in the reticuloendothelial cells of the spleen, liver, and bone marrow
Bilirubin
Bilirubin
Specimen must be…
Avoid…
Fresh
Avoid exposure to sunlight
Bilirubin
• Mechanical test to detect the presence of bilirubin in dark yellow - brown or amber urine specimens.
• Produced a distinct “yellow foam” when agitated
Foam Shake Test
• The tablet contains: p - nitrobenzene diazonium p - toluene sulfonate, sulfosalicylic acid, and sodium bicarbonate
• Take note that the tablets are hygroscopic
Diazo Tablet Method
• Also known as the “Ictotest Tablet Test”
Diazo Tablet Method
• Also known as the “Ictotest Tablet Test”
• This test reacts positively to bilirubin in amounts as low as____ to ____
0.05 to 0.1 mg/dL.
Bilirubin
Diazo Tablet Method
• Also known as the “Ictotest Tablet Test”
Procedure:
1. Place 10 drops of urine on an____
2. Place a reagent tablet on the moistened area of the mat.
3. Place one drop of____ onto the tablet. Wait 5 seconds, then place a second drop so that the water runs off the tablet onto the mat.
4._____ color positive; _____color - negative
asbestos - cellulose mat.
water
Purple
pink or red
represents a group of closely related tetrapyrrole compounds
formed from reduction of bilirubin.
Urobilinogen
• is normally present in the urine but in concentrations of 1 mg/dL or less, which is approximately equal to 1 EU
Urobilinogen
• Urobilinogen is____, as opposed to the urobilin
colorless
Urobilinogen
^ in ____ urine
V in ____ urine
Alkaline
Acidic
• The reagent strip is not specific for urobilinogen, and will detect substances known to react with the Ehrlich reagent
• Porphobilinogen
• P - aminosalicylic acid metabolites
• Sulfonamides
• Procaine
• 5 - hydroxyindoleacetic acid
• Indole
• Methyldopa
• Ehrlich aldehyde reaction, and based on solubility between urobilinogen and porphobilinogen
• Urobilinogen can be extracted by
chloroform and/or butanol, whereas
porphobilinogen will remain in an
aqueous phase.
Watson - Schwatz Test
Urobilinogen
Watson - Schwatz Test (Procedure)
•_______+______, mix.
Add 5mL saturated sodium acetate and mix
Add 5ml of chloroform. Insert stopper and shake vigorously for
1 minute. Allow phases to separate
• Examine the upper (aqueous) phase. If the color is absent, consider the result of the screening test to be negative and stop.
• If color is present, separate the upper phase and add 5mL butanol. Insert a stopper and shake vigorously for 1 minute.
Allow phases to separate.
2.5 mL fresh urine + 2.5 mL Ehrlich reagent
Watson - Schwatz Test (Procedure)
• A “______” color in the lower aqueous layer indicates positive
result and suggests concentration of
porphobilinogen that is several times normal.
A color in the upper butanol layer indicates an increase in urobilinogen concentration.
pink to rose red
• The addition of a _____testing area to reagent strips has eliminated a time-consuming step in routine urinalysis and has provided a convenient method for routine screening.
specific gravity
Pads are impregnated with: polyelectrolyte, indicator substance, and buffer
SG
SG
(dec. H+)
-→ –.
(inc. H+)
-→
(markedly inc. H+)
BLUE
GREEN
YELLOW
Detects the presence of esterase in the granulocytic white blood cells
Leukocyte esterase
• also are present in Trichomonas and histiocytes
• Screening for UTI also includes pH, protein, and nitrite.
Leukocyte esterase
• Provides an important tool to identify UTI (cystitis or pyelonephritis)
Nitrite
• Most common infection microorganism (KEEP)
• Causing UTI but do not reduce nitrate to nitrite (2)
Klebsiella spp.
Escherichia coli
Enterobacter spp.
Proteus spp.
Staphyloccoccus saprophyticus and Enterococcus spp.
_____ at an acidic pH reacts with an aromatic amine (para-arsanilic acid or sulfanilamide) to form a diazonium compound that then
reacts with tetrahydrobenzoquinolin
compounds to produce a pink colored azodye.
Nitrite
