Chemistry Examination Flashcards
Unmixed Specimen (_ and _ sink at the bottom)
RBC & WBC
reagent strip timing for reaction for pH
immediately
reagent strip timing for reaction for leukocyte esterase
120s
reagent strip timing for reaction for the rest of parameters
60 -120s
reagent strip ph principle
Double indicator system
pH Reagent Strip Reaction:
Double indicator system of _ and _
methyl red and bromthymol blue
ph color changes
red - yellow - blue
pH rx
Methyl Red → Red to _ (pH _)
Yellow; 4-6
pH rx
Bromthymol Blue → Yellow to _ (pH _)
Blue; 6-9
reagent strip pH reagents:
Methyl Red, Bromthymol Blue
reagent strip pH sensitivity
Multistix: 5.0-8.5 in 0.5 increments
Chemstrip: 5.0-9.0 in 1.0 increments
chemstrip increments for pH parameters
1.0
reagent strip pH interferences
- No known interfering substances
- Run-over from adjacent pads
- Old specimens
reagent strip pH correlations
nitrite, leukocyte, microscopic
causes of acidic 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
the inability of a person to produce an acid urine due to an impaired ammonia production
Renal tubular acidosis
Renal tubular acidosis has _ urine
alkaline
causes of alkaline urine
- Hyperventilation
- Vomiting
- Renal tubular acidosis
- Presence of urease producing bacteria
- Vegetarian diet
- Old specimen
reagent strip protein principle
Protein error of indicator
protein error of indicators to produce a _ reaction
visible colorimetric
reagent strip protein reaction:
the protein area of the strip contains reagent and an _ to maintain _ at a constant level
acid buffer; pH
reagent strip protein reaction:
At a pH level of _, both indicators appear _ in the absence of protein.
however, as the protein concentration increases, the color progresses through various shades of _ and finally to _
3; yellow
green; blue
protein trace value (reagent strip)
<30mg/dL
reagent strip protein reagents
Multistix: tetrabromophenol blue
Chemstrip: 3’,3”,5’,5”-tetrachlorophenol, 3,4,5,6-tetrabro- mosulfonphthalein
reagent strip protein reporting:
negative, trace, 1+, 2+, 3+, and 4+; or the semiquantitative values of 30, 100, 300, or 2000 mg/dL
reagent strip protein sensitivity
Multistix: 15 - 30 mg/dL albumin
Chemstrip: 6 mg/dL albumin
reagent strip protein interferes
False-positive:
- 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-negative
- Proteins other than albumin
- Microalbuminuria
if a px is allergic to iodine as antiseptic, use _
chlorhexidine
reagent strip protein correlation
blood, nitire, leukocyte, microscopic
reagent strip glucose principle
Double sequential enzymatic reaction
reagent strip glucose reaction
Glucose Oxidase
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 testing
Glucose oxidase testing method by impregnating the testing area with a mixture _, _, _, and _ to produce a double sequential enzyme reaction
glucose oxidase, peroxidase, chromogen, and buffer
reagent strip glucose chromogens
Multistix: potassium iodide (green to
brown)
Chemstrip: tetramethylbenzidine
(yellow to green)
t/f. multistix & chemstrip glucose parameter has same reagents but different chromogens
true
reagent strip glucose color reaction (multistix)
reagent strip glucose color reaction (chemstrip)
green to brown
yellow to green
reagent strip glucose reporting
Negative, Trace, 1+, 2+, 3+, 4+
reagent strip glucose sensitivity
- Multistix: 75-125 mg/dl
- Chemstrip: 40 mg/dl
reagent strip glucose correlations:
ketones and proteins
reagent strip glucose interferences
False-positive
Contamination by oxidizing agents and detergents
False-negative
High levels of ascorbic acid
High levels of ketones
High specific gravity
Low temperatures
Improperly preserved specimens
reagent strip protein reaction (clinitest)
copper reduction test
test for reducing sugars; can detect other reducing sugars except sucrose
copper reduction test
copper reduction test can detect other reducing sugar except
sucrose
copper reduction test relies on the ability of glucose and other
substances to reduce _ to _ in the presence of alkali and heat
copper sulfate; cuprous oxide
copper reduction test color change
neg blue - orange/red
blue, green, yellow, orange/red
“PASS-THROUGH” phenomenon is observed in what test
copper reduction test
reagent strip glucose interferes(clinitest)
other reducing sugars (galactose, lactose, fructose, maltose, pentoses, ascorbic acid, certain drug metabolites, and antibiotics such as the cephalosporins