Chemical Examination pt.2 Flashcards
__ cells/uL of RBC is clinically significant
5
False positive reactions for blood
Menstrual contamination
Strong oxidizing reagents
Vegetable or bacterial peroxidase
Principle for the reagent strip for blood
Pseudoperoxidase activity of hemoglobin
Modified true or false:
Myoglobin and hemoglobin has increased CK in myogloninuria and hemoglobinuria
True
Historical test for differentiating hemoglobinuria and myoglobinuria
Ammonium sulfate precipitation
What are the 3 types of jaundice
Pre-hepatic
Hepatic
Post-hepatic
Pre-hepatic increase in bilirubin may be due to what?
Increased heme degredation
Hepatic increase in bilirubin may be due to what?
Hepatocellular disorders
Pre-hepatic increase in bilirubin may be due to what?
Obstruction after the liver
Urobilinogen and bilirubin levels in pre-hepatic jaundice in the urine
High urobilinogen
Low bilirubin
Urobilinogen and bilirubin levels in hepatic jaundice in the urine
Normal to high urobilinogen
High bilirubin
Urobilinogen and bilirubin levels in post-hepatic jaundice in the urine
Low urobilinogen
High bilirubin
Why is there an increased urine bilirubin in hepatic jaundice?
The liver recirculates the majority of bilirubin into the kidney
In post-hepatic jaundice, what causes the increased bilirubin? Why?
Increased bilirubin is increased due to obstruction. Since there is an obstruction, bilirubin cannot be converted to urobilinogen.
What is the reagent strip reaction called for bilirubin, and explain how it works
Diazo reaction
Conjugated bilirubin + diazonium salt = Azobilirubin
False positive reactions for bilirubin
Highly pigmented urine
Indican
Metabolites of iodine
False negative results for bilirubin
Exposure to light
Ascorbic acid
High nitrite concentrations
What is the confirmatory test for bilirubin?
Ictotest tablets
___ drops of urine must be placed on an absorbent test mat
10
How long can the color change be observed in Ictotest?
30 seconds
Normal concentration of urobilinogen
1 mg/dL or less
Urobilinogen can be tested after ____ hours after mid-day meal
2
When urobilinogen oxidizes, it turns into _____
Urobilin
What is the old quantitative method for screening urobilinogen
Classic Ehrlich’s reaction
Ideal specimen for nitrite testing
First morning urine
Reagent strip reaction for nitrite
Greiss reaction
Minimum amount per hpf for leukocyte esterase
20/hpf
