URINALYSIS LAB

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URINALYSIS LAB

Purpose:

• To observe and analyze a urine sample

Introduction:

The kidneys produce urine in the nephrons through three processes: glomerular filtration, tubular

reabsorption and secretion. As blood is filtered in the nephrons, waste products and toxins are removed

from the blood and the balance of water and electrolytes is maintained. Every day, the body produces

between 1 and 2 liters of urine. The volume and composition of urine varies according to hydration, diet,

environmental temperature and other factors.

Urinalysis (UA) is the analysis of the physical, chemical and microscopic characteristics of urine. It is

used to evaluate kidney function. The physical characteristic involve transparency, color, odor and

volume. The chemical characteristics include evaluation of urine for the presence of urea, electrolytes,

bilirubin, hemoglobin, glucose, proteins, ketones and other. The specific gravity of urine tells us about

the concentration of solutes in urine, normal values are from 1.000 – 1.0030; the greater the amount of

solutes in urine, the greater the specific gravity.

A microscopic examination of the solids in urine which are obtained after centrifugation of a volume of

urine, allows us to see epithelial cells, casts, crystals or even bacteria that may be present in urine.

Pre-Lab: use your textbook to answer the following questions.

1. Name the instrument used to determine specific gravity

2. Define specific gravity

3. How is specific gravity related to concentration?

4. Where should you place Urine at the completion of the test?

5. Use your textbook to fill out the normal results and causes of abnormal results on Page 3 of this handout.

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Materials: • Disposable urine collection cups

• Simulated Urine Samples

• Pipettes

• Urinometer cylinder

• Urinometer hydrometer • Chemstrips to test for the presence of

Glucose and Proteins

Procedure: 1. Pour out small amount of unknown urine sample from the bottle into a small plastic cup..

Physical characteristics:

1. Observe the sample and describe the physical characteristics such as transparency, color, and

odor.

2. Record your data in the table provided.

3. Now pour out the urine from the plastic cup and into the urinometer cylinder until the cylinder is 2/3 full.

4. Place the urinometer hydrometer in the urinometer cylinder, make sure the hydrometer is

floating freely in the urine.

5. Place your eyes at the level of the urine and record the number by the line that intersects with

the lower meniscus of the urine. Record your value.

6. Pour the urine back in the collection cup/bottle.

7. Wash, clean, dry and place the hydrometer and cylinder back into its own box.

Chemical characteristics: pH 1. Place a pH strip in the urine, remove at an angle while touching the sides of the cup to

remove excess urine from the strip.

2. Compare strip to color coded chart on the container bottle. Complete the reading within

2 minutes of wetting the strip.

3. Record the pH of your sample on Page 3.

4. Dispose off strip in the regular trash bin.

Chemical characteristics: Glucose and Proteins

1. Observe the color of the test squares that are attached at one end of the urine

Reagent strip. The greenish square nearest the tip will be used for testing the

Gluose in the sample; the yellow square will detect protein in the sample.

2. Dip the end of the strip with the test squares into the urine sample, and then

withdraw it. Run the end of the strip against the rim of the urine container to

remove excess urine.

3. Wait for at least 30 seconds and then compare strip to the unused strip, which

would be your control sample.

a. Green square: A negative result produces no color change, indicating normal

or low urine glucose. A darkening of the square indicates a higher than

normal urine glucose level; the darker the color, the higher the glucose level.

b. Yellow square: A negative result produces no color change, indicating the

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absence of protein in the urine. A green or blue color indicates the presence

of protein in the urine sample.

4. Dispose of strip in the regular trash bin.

Clean up:

1. Wipe the tables clean with alcohol.

2. Wash your hands.

Results: Use your observations from this lab activity to fill in your results in this chart. Use your textbook to find out any cause/s of the abnormal results.

CHARACTERISTIC NORMAL CAUSE/S OF ABNORMAL RESULTS

YOUR RESULTS

Color

ODOR

TURBIDITY

SPECIFIC GRAVITY

pH

GLUCOSE

BILIRUBIN

KETONES

BLOOD

WHITE BLOOD CELLS

PROTEIN

NITRTITES

UROBILINOGEN

LEUKOCYTES

OTHER

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ANALYSIS:

1. Where do the epithelial cells found in the urine sediment come from?

2. When would you expect to find glucose in the urine?

3. Identify normal and abnormal ingredients of urine sediment.

4. How would glucose in the urine influence specific gravity?

5. Why might glomerular inflammation result in the presence of blood and protein in the urine?

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