Chemical Examination of Urine: pH and Protein Flashcards
major types of reagent strips used:
- Multistix (Bayer)
- Chemstrip (Roche-Boehringer Mannheim Diagnostics)
reagent strips be stored at:
room temperature below 30°C (but never refrigerated)
________ a frequent constituent of renal calculi, precipitates primarily in acidic and not alkaline urine.
calcium oxalate
Maintaining acidic urine can be valuable in treating
UTIs caused by urea-splitting organisms
a color change from red to yellow in the pH range 4 to 6
Methyl red
turns from yellow to blue in the
range of 6 to 9
Bromthymol blue
Sources of error/interference
No known interfering substances
Runover from adjacent pads
Old specimens
Bacterial growth
Does normal urine contain very little protein? usually?
less than 10 mg/dL or 100 mg per 24 hours is excreted
the major serum protein found in normal urine.
albumin
produced by the renal tubular epithelial cells; and proteins from prostatic, seminal, and vaginal secretions. a glycoprotein, is produced routinely in the ascending loop of Henle
Tamm-Horsfall protein (THP), also known as
uromodulin,
Clinical proteinuria is indicated at
30 mg/dL or greater (300 mg/L)
3 major categories of proteinuria:
- prerenal
- renal
- postrenal
caused by conditions affecting the plasma before it reaches the kidney and therefore is not indicative of actual renal disease.
Prerenal Proteinuria
increased levels of low-molecular weight plasma proteins, such as:
hemoglobin, myoglobin, and
the acute-phase reactants
A primary example of proteinuria due to increased levels of serum protein is the excretion of
Bence Jones protein by people
with multiple myeloma
perform Solubility Test to confirm kani tong i-boil ang urine unya if naay coagulation or precipitation tas mag dissolve sa 100 C
si Bence Jones, abnormal protein man ni
associated with true renal disease may be the result of damage to the glomerular membrane or tubular dysfunction.
Renal Proteinuria
Additional parameters:
- ascorbic acid
- microalbumin
- creatinine
- calcium
Improper technique includes:
a. unmixed specimen (sediments settle at the bottom and cannot be detected)
b. allowing the strip to remain in urine for an extended period of time
c. performing the reagent strip technique immediately after refrigeration (should be at RT)