Body Fluid Lab. Report
Chemical Examination of Urine
Prepared By :
Benedict's Test for Reducing Sugars
Urinary sugars when boiled in Benedict's reagent reduce copper sulphate to a reddish cuprous oxide precipitate in hot alkaline medium, the intensity of which is proportional to the amount of sugar present in the urine. The results are reported as 1+,2+, etc. depending upon the colour and intensity of the cuprous oxide precipitate.
turbidimetric method protein in urine
Quantitative Tests for 24-Hour Specimens.Trichloroacetic acid (TCA) test. The addition of TCA to a urine specimen precipitates the protein in a fine suspension that is quantified spectrophotometrically at 420 nm (nanometers) by comparison with a similarly treated standard.
Heat and acetic acid method
Heat test: Based on the principle of heat coagulation and precipitation of proteins. If any turbidity appears, add 2 drops of 33% acetic acid. (Acidification is necessary because in alkaline medium heating may precipitate phosphates). If the precipitate is due to proteins, it will increase on acidification and if it is due to phosphates, it will dissolve again.
Sulphosalicylic acid method
Urine Protein Sulfosalicylic Acid Precipitation Test (SSA) Principle: Three percent (3%) Sulfosalicylic Acid (SSA reagent) is added to a small and equal volume of clear urine. The acidification causes precipitation of protein in the sample (seen as increasing turbidity), which is subjectively graded as trace,1+, 2+, 3+ or 4+. Bence Jones protein
Bence Jones reaction involves heating urine to 140°F (60°C). At this temperature, the Bence Jones proteins will clump. The clumping disappears if the urine is further heated to boiling and reappears when the urine is cooled. Other clumping procedures using salts, acids, and other chemicals are also used to detect these proteins. These types of test will reveal whether or not Bence Jones proteins are present, but not how much is present.
Hemosiderin stain is used to indicate the presence of iron storage granules called hemosiderin by microscopic examination of urine sediment. Granules of hemosiderin stain blue when potassium ferrocyanide is added to the sample. The Prussian blue stain may also be used to identify siderocytes (iron-containing red blood cells [RBCs]) in peripheral blood. The presence of siderocytes in circulating RBCs is abnormal.
This test is based on a modified Ehrlich reaction in which p-diethylaminobenzaldehyde reacts with urobilinogen in a strongly acid medium. Colors range from light pink to bright magenta. Results
* Benedict's Test result for cup # G3 :
4+ Brown color appear.
* Turbidimetric method result for cup of 24-hrs urine:
Standard+water blank| 0.010|
Total protein (mg/dl)=At/Ast × conc. St
0.058/0.010 ×100=580 mg/dl
Total protien(mg/24 hrs) =urine protein (mg/dl)×urine volume(ml)/100 = 580×(2000/100)=11600 mg /dl
Normal values :0-150 mg/24 hrs
* Heat and acetic acid method and Sulphosalicylic acid method for cup # P4:
4+ precipitation appeared.
* Bence Jones protein for cup # P4 :
Clear after 15 min of boiling so negative for Bence Jones protein.
* Hemosiderin results :Few Hemosiderin granules was seen under Microscope
* Urobilinogen result for cup # G3:Negative result (no appearance of red color).
Benedict's Test for Reducing Sugars
Normal urine does not contain any reducing sugar. If protein is present in large amounts, it may interfere with the precipitation of the cuprous oxide.To overcome this problem, precipitate the proteins using 3% SSA filter using a Whatman filter paper and use the filtrate to test the amount of sugar...