In this package, the student will study the physical and chemical composition of urine as well as the neural control of micturition.

This knowledge will assist the student in assessing the clients need for elimination.

BEFORE YOU DO THE URINALYSIS EXPERIMENT BELOW YOU MUST:

Make sure that you have read and understand the page on Handling of Body Fluids in the Introduction.

Completed and signed a new safety contract and turned it into the lab.

Read the specific procedures for handling and disposal of materials used in the Urinalysis experiment on the following page.

Answer the following questions on the handling and disposal of materials used in this lab:

• What should you do with the test strips and the pipet used in this experiment?
• What should you do with the urine sample that you have tested after you have completed this experiment?
• What should you do with the urinometer and cylinder after you have finished this experiment?

HANDLING AND DISPOSAL OF MATERIALS USED IN THE URINALYSIS EXPERIMENT

Four different urine samples (labeled A, B, C & D) will be available in the lab. Please pick one for your urine analysis.

Only 4 students at a time will be permitted to do the urinalysis. There will be 4 work stations set up in the lab for this purpose and no other students will be allowed in this area. There will be a waiting list for work stations. Please put your name on this list if there are no stations available, and cross it off when a station becomes available.

When you go to a work station put on a pair of gloves and an apron. Using a paper towel wipe the tray with 10% bleach. Discard the paper towel in the Biohazard Container. Put a fresh piece of white paper towel on the tray. Do all of your tests on the tray.

Keep all of your used test strips on the paper towel and then throw the towel and the strips in the Biohazard

Container after you have finished all of your tests.

Dispose of the plastic pipet used with the Ictotest in the Biohazard Container.

After you have finished all of your tests pour your urine sample into the urine waste container available in the lab and dispose of your sample cup in the Biohazard Container.

The urinometer and cylinder must both be washed after use. Use the sink designated for this purpose. Rinse the cylinder with 10% bleach solution and then again with water. Shake as much excess water out of the cylinder as possible, and turn it upside down on the tray beside the sink. Rinse the urinometer with 10% bleach solution and then with water, and leave it on the tray.

Using a paper towel, wipe the tray at the work station with10% bleach and discard the towel in the Biohazard Container. Dispose of your apron and gloves in the Biohazard container.

Lab Activity – Urinalysis Introduction

Urinalysis is a valuable tool for the diagnosis and management, not only of kidney disease but also of malfunction of other body systems, since the nature and composition of the urine reflects many metabolic processes in the body. Urine flow and composition is subject to wide diurnal variation, and is dependent on fluid intake, diet, exercise, emotional phenomena and other normal variables.

Clinical assessment is therefore often based on analysis of a 24 hour sample. In this exercise, we will examine urine from a control sample collected as part of this exercise. Considerable individual variation is to be anticipated.

Materials Required:

• Specimen cup Urinometer Urine test strips
• Gloves and aprons
• Pipet
• Download Urinalysis Data Sheet [DOCX] to use during this lab activity.

As you complete each test please record the results in the urinalysis data sheet provided above. Note that you need to record the name of the test used, the normal value and the result of your test.

Part A – Collection of Urine

Four different urine samples (labeled A, B, C & D) will be available in the lab for urinalysis. Please pick one sample for your urinalysis. Do not forget to record your sample’s ID in the urinalysis data sheet.

Part B – Urinalysis: The Tests

When you go to the work station put on a pair of gloves and an apron. Put a fresh piece of white paper towel down on the tray. Do all of your tests on the tray.

Keep all of your used test strips on the paper towel and then throw the towel and the strips into the biohazard container after you have finished all of your tests.

Appearance

Normal urine varies from light yellow through straw colour to amber. The colour is dependent on concentration, and varies with colour imparted by food items (e.g. beets) in the diet as well as by normal metabolites produced by the body. Freshly voided urine is normally clear, but turbidity may result for a variety of reasons, especially after the urine has been standing for some time.

1. Record the colour and turbidity of your urine sample in the Urinalysis Data Sheet of this package.

Odour

Normal urine has a distinctive aromatic odor. Urine which has been allowed to stand for some time smells of ammonia due to the conversion of urea to ammonia. Different odors are noted after the ingestion of certain foods (e.g. asparagus), or in disease conditions (e.g. odor of acetone in urine from individuals with Ketosis).

2. Record the odor of your urine sample in the Urinalysis Data Sheet of this package.

Volume

The 24 hour volume is not recorded in this exercise, and the volume of a single sample has no clinical significance.

3. Look up and record the normal range for the 24 hour volume in the Urinalysis Data Sheet of this package.

Specific Gravity

Normal range for the pooled 24 hour sample is 1.016 to 1.025. Individual samples may vary between 1.002 (after ingesting large amounts of fluid) and 1.040 (when perspiring heavily).

4. Mix the urine well by shaking the vial.
5. Fill the cylinder about 3/4 full of your sample and place hydrometer float in the sample.
6. Read the specific gravity from the scale on top of the hydrometer scale. The normal range for specific gravity is 1.005 to 1.030.
7. Record your result in the Urinalysis Data Sheet.

DO NOT DISCARD YOUR SAMPLE

pH

Normal values of individual samples range from 4.5 to 8.0, but the pooled 24 hour sample is usually slightly acid – about pH 6.0. This varies with diet – the urine of vegetarians is usually less acidic.

pH Determination

8. Dip a strip of pH paper in the urine and match the colour which develops with the colour chart on the pH dispenser. The pH for urine is normally between 5.0 and 7.5.
9. Record to the nearest 0.5 pH units in the Urinalysis Data Sheet of this package.

Protein

Normal urine contains very little protein (less than 250 mg/day). Transient proteinuria may be observed following heavy exercise, after a high protein meal or, particularly in children and young adults, on standing erect (postural proteinuria). In 30-35% of cases, pregnancy is accompanied by proteinuria.

10. To test for protein, dip the end of the Albustix strip in the urine sample, shake off the excess by tapping on the edge of the container and read by comparing with the colour chart on the Albustix container.

Glucose and Other Reducing Substances

Glucose and other reducing sugars (galactose, lactose, fructose) are normally not present in urine. Although these substances are filtered in the renal corpuscle, all are normally totally reabsorbed in the proximal tubule.

Using Keto-Diastix to test for Glucose

11. Completely immerse the reagent area of the strip in fresh urine and remove immediately, tapping the edge of the strip on the urine container to remove excess. Compare the test area with the provided colour chart and read your glucose result at exactly 30 seconds after you remove the strip from the urine.

Ketones

Ketone bodies are normally absent from urine, but may be found following anesthesia, expo- sure to cold or severe exercise or with carbohydrate restricted diets, as well as in a variety of pathological conditions such as diabetes mellitus or starvation. Ketone bodies are inter- mediate products in triglyceride (fat) metabolism and include the acetoacetic acid, betahydroxybutyric acid and acetone.

Normally most of these that are produced are used in aerobic respiration, but when fat metabolism is excessively stimulated, the concentration of ketone bodies in the blood exceeds the rate at which they can be utilized, and they appear in the urine.

12. Dip the test end of the Ketostix in urine and remove immediately. Compare with the colour chart provided on the container and read.

Occult Blood

Blood is not a normal constituent of urine. The test is sensitive to hemoglobin (and myoglobin) which may be free in urine, as a result of red cell lysis, or present in intact red cells. A positive test is an indication for examination of the urine for red blood cells. The test is more sensitive to free hemoglobin than to intact red cells.

13. Dip the end of a Hemastix test strip in the urine sample, shake off excess, and compare with the colour chart on the container.

Bilirubin

Old, worn out red blood cells are broken down in the spleen. When the hemoglobin molecule is broken down bilirubin is produced. The bilirubin molecule must be transported to the liver in the blood. To do this it is attached to albumin. One reason for forming this bilirubin-albumin complex (called conjugated bilirubin) is so that it will be too large to pass through the glomerulus into the nephron. For this reason there is no bilirubin normally found in the urine. Once in the liver, the bilirubin is detached from the albumin. Now the liver cells put bilirubin into the bile. It will then go to the small intestine.

14. Obtain a special ictotest mat, and put five drops of urine on it using a clean dropper. Place an ictotest tablet in the centre of the moistened area. Add two drops of water on top of the tablet. A positive test is indicated if the mat around the tablet turns blue or purple within 30 seconds.

Cleaning Up

The urinometer and cylinder must both be washed after use. Use the sink designated for this purpose. Rinse the cylinder with a 10% bleach solution, and then with water. After washing the urinometer, dry it with a paper towel and leave it on the tray.

After you have finished all of you tests pour your urine sample into the urine waste container available in the lab and dispose of your sample cup in the Biohazard Container.

Dispose of your gloves, apron, and used test strips in the Biohazard container.

Evaluation

The data table must be filled out as indicated before you are evaluated.

In column 1 of the data table make sure that you have recorded both the name of the test used, and the normal value for that test. In column 2 record the result that you got for your own urine sample.

Using your knowledge of nephron structure and function explain why you would get the normal values for each test.

Using the information from the tables in your text you should be prepared to discuss what might cause abnormal results.

Review

Which of the following are normal characteristics of urine?

• Colour: Red,  Amber,  Pale Yellow,  or Orange?
• Clarity: Clear, or Cloudy?
• Contents: Glucose,  Sodium,  Mucous Strands,  Albumin,  Urea,  Erythrocytes,  Creatinine,  or Leukocytes?
• Specific Gravity: 1.000, 1.010, 1.025, or 1.030?
• Average pH: 2, 4, 6, or 8?
• Amount Voided in 24 hrs: 500 cc, 1500cc, or 3500cc?