Clinical Biochemistry

1. URINE ANALYSIS

2. Urine dipstick
• Screening for disease
• Fresh urine is collected into clean dry
container
• Reagent strip immersed in the urine
specimen, ensure all the reagent blocks are
covered.
• Errors in results

4. • Three urine samples are shown. The one at the left shows a
red, cloudy appearance. The one in the center is red but clear.
The one on the right is yellow, but cloudy.

5. Parameters in urine dipstick test
• Glucose
• Bilirubin
• Urobilinogen
• Ketones
• Specific gravity
• pH
• Protein
• Blood
• Nitrite
• Leucocytes

6. Physical examination of urine
• Volume
a) physiological factor
-increase intake of water
-temperature
-physical activity
-others due to diuretic drugs, coffee and alcohol
-normal adult urine volume : 600-1200ml/hour
-difference in urine volume due to:
polyuria, oliguria, anuria and nocturia

7. • Colour
- normal : pale yellowish- urochrom pigment
- abnormal : due to food intake and drugs
Red : beets, rhubarb (alkaline urine)
Orange-yellowish : carrot, antibiotic
Green, blue-green : drugs eg: amitrypline
Dark brown : drugs eg: methyldopa, metronidazole
- abnormal : due to pathological
Red/maroon : rbc, hemoglobin, myoglobin
‘wine-red’ : porphyrin
Dark brown : melanin, homogentisic acid
Yellowish-brown or
greenish-brown : bilirubin, bile pigment

8. • Odour
normal: aromatic odour
- Food and drugs causes characteristic odour
e.g: methyl salicylic, asparagus
- Ketosis : fruity/sweet
- Congenital metabolism disorder : e.g:
phenylketonuria ‘mousy’

9. • Appearance/ transparency
Normal:
-Slight turbidity: mucus (in women), squamous
epithelial cell
-Turbidity: calcium oxalate, uric acid, amorphous
phosphate, amorphous urates
Abnormal:
-turbid-red : rbc
-turbid : bacterial or yeast infection
-milky: lipid

10. Normal urine composition
• Urea
- End product of protein metabolism
- 50% from urine composition
- 25-30 g/24hr
• Uric acid
- End product of purine metabolism
- 0.5-1 g/24hr
• Creatinine
- Skeletal muscle tissue

11. • Creatine
- Can be found in muscle tissues in form of
phosphocreatin
• Sulphur
- Protein intake
• Indican
- Triptophan katabolism in intestine
• Ammonia
- Final product of protein metabolism

12. • Chloride
- Second largest composition found in urine
- Excreted in form of NaCl : 10-15g/24hr urine
• Phosphate
- Protein intake
- 1.1g/24hr urine

13. Pathological urine composition
• Glucose
• Protein
• Ketones
• Pus cells
• Red blood cells
• Lipid
• Amino acid
• Bile pigment
• Calculi

14. Microscopic sediment of urine
• Cells
-rbc, wbc, squamous epithelial cells, urethral epithelial cells
• Casts
- Represent a collection of protein and cellular debris in a
kidney tubule
- Eg: hyaline : occasionally found in normal urine but their
number is increased in renal diseases.
- Cellular cast: one or more type of cells are trapped during
their formation. Eg; pus cell casts, red cell casts, epithelial
casts, and mixed cellular casts.
- Granular casts : fine granules appear in glomerular and
tubular renal disease.

15. Cyrstals
• Uric asid
• Amorphous urates
• Amourphous phosphate
• Calcium oxalate
• Triple phosphate
• Calcium carbonate
• Tyrosine
• Leucine
• Cystine
• Cholesterol

16. • Red blood cells in urine appear as refractile disks.
With hypertonicity of the urine, the RBC's begin to
have a crenated appearance

17. • These white blood cells in urine have lobed nuclei
and refractile cytoplasmic granules.

18. • Large polygonal squamous epithelial cells with small
nuclei are seen here.

19. • Oval fat bodies consist of degenerated tubular cells
containing abundant lipid, which appears refractile.

20. broad (Figure 3).
Urinary casts. (A) Hyaline cast (200 X); (B) erythrocyte cast (100 X); (C)
leukocyte cast (100 X); (D) granular cast (100 X).

21. Urinary crystals. (A) Calcium oxalate crystals (arrows; 100 X); (B) uric acid
crystals (100 X); (C) triple phosphate crystals with amorphous phosphates
(400 X); (D) cystine crystals (100 X).

22. Type of Urine Sample & Collection
Sample Sampling Purpose
Morning sample First urine in the Pregnancy test,
morning microscopic test
Random sample No specific time Routine screening,
chemical & FEME
Postprandial 2 hours after meal Determine glucose in
diabetic monitoring
Midstream/clean Discard first few ml, Culture
match collect the rest
2 hours Within 2 hours period Determine urobilinogen
24 hours Within 24 hours period Determine renal
function