Download Biol 204 Urinalysis Lab Objective: Analyze an initial urine sample

Biol 204 Urinalysis Lab
Objective: Analyze an initial urine sample and a urine sample after experimental conditions
Experimental Groups:
A) Group 1: SALTY Chips!! (1 lunch bag size of salty chips)
**Note: after you consume the chips, do not consume any liquid until the experiment
has been completed!
B) Group 2: Highly caffeinated soda (1 can super mountain dew or something with a large amount
of caffeine)
C) Group 3: Plain water (Amount equivalent to size of soda can)
D) Group 4: Diet Soda
E) Group 5: Nothing (Control)
*DO NOT eat or drink anything for the rest of the experiment after you have consumed your assigned
substance.
Procedure:
1) Grab a beaker and go pee!  (Try to collect all your urine output if possible)
2) Return to lab and immediately eat or drink whatever you are experimental variable you are
assigned (try to consume it within a maximum of 5min). Once you finish eating or drinking
record this time and start counting the 30min until collecting the next urine specimen.
3) Wait 30min to see the affect the experimental variable has on your urinary system
4) While you are waiting conduct the following tests and observations:
a. Use your chemstick (dipstick) and pH strip to analyze urine
i. Chemstick (dipstick): dip the stick in the urine so that urine touches all pads on
the strip. Wait one minute, then compare the colors on the strip to the standard
colors on the container and record your results.
ii. pH chart
b. [NaCl] Concentration:
i. to measure NaCl concentration, put 10 drops on urine in a test tube.
ii. Add 1 drop of 20% potassium chromate (the yellow stuff)
iii. Add silver nitrate dropwise (count the drops!!) until brown color appears and
does not disappear upon gentle agitation of the tube.
1. Each drop of silver nitrate represents 1 gram of NaCl per liter of urine,
so: [NaCl] = 1g/L x (number of drops of silver nitrate)
c. Specific Gravity: You will be using a Refractometer to determine the specific gravity of
your urine. A Refractometer is an instrument that measures the relative concentration
of solutions as compared to distilled water (note: distilled water should not have
dissolved solutes. Its specific gravity should be 1.000 (no units)).
i. apply 1 or 2 drops of urine to the surface of the refractometer.
ii. standing under the light, look through the eyepiece and determine the specific
gravity of the urine
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5)
6)
7)
8)
iii. if you’re unfamiliar with the refractometer and need help using it I am happy to
help you
d. Observation Test:
i. Analyze your urine based on
1. Color
2. Transparency
3. Total volume
4. Odor
ii. Record your results on the chart provided
After 30min empty your measuring cup and go and pee again and collect another urine sample!
(You will do this for 30min, 60min, and 90min, after eating or drinking whatever you were
assigned)
For each sample (30min, 60min, 90min) conduct the following 3 tests:
a. Volume
b. Specific Gravity
c. [NaCl]
Record your data on the charts provided and then record the averages on the board (time 0 is
your initial sample)
Compare and discuss your results from the initial, 30min, 60min, and 90min intervals and
answer the following questions. (Think about hormones like ADH and Aldosterone and what
influences they will have; think about your sensation for thirst/or lack of sensation of thirst and
why this could be; think about diuresis and whether or not your results demonstrate diuresis
and why in your discussion.)
Questions:
1. How did the results of your Chemstick Test compare to the normal/expected values you
located in your book or on the Internet? Were any of your test results abnormal? If so, give a
logical explanation as to why (for ex: women who are menstruating may test positive for red
blood cells in their urine).
2. Name the treatment to which you were assigned in Activity 5. Describe any ingredients in
your treatment (i.e. caffeine, sugar, artificial sweeteners, sodium) that may have influenced
the production of your urine. Specifically, explain how the intake of each ingredient (describe
each separately!) should influence: A) body fluid osmolarity, B) urine output (volume) and C)
urine specific gravity.
3. Did your group experience a change in urine volume over time? If so, in which direction?
Does the change in urine volume fit with what you would predict given your particular
treatment? Explain why or why not.
4. Did your group experience a change in specific gravity over time? If so, in which direction?
Does the change in specific gravity fit with what you would predict given your particular
treatment? Explain why or why not.
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5. By the end of the laboratory period, which treatment group (not including the control) had the
largest increase in urine output (volume)? Don’t just look at the final value but rather the final
minus the initial value! Is this what you would expect? Why or why not?
6. By the end of the laboratory period, which treatment group (not including the control) had the
largest increase in urine specific gravity (look at final minus initial)? Is this what you would
expect? Why or why not?
7. By the end of the laboratory period, which treatment group had the highest concentration of
ADH circulating in the body? Which had the least? Explain your answers.
8. Assuming normal conditions, note whether each of the following substances would be (a)
more concentrated in urine as opposed to the glomerular filtrate, (b) more concentrated in
the glomerular filtrate as opposed to urine, (c) equally concentrated in both urine and the
glomerular filtrate, or (d) absent in both.
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
m.
Water ____
Phosphate ions ____
Sulfate ions ____
Potassium ions _____
Sodium ions _____
Amino Acids _____
Glucose _____
Albumin _____
RBCs _____
WBCs _____
Urea _____
Uric Acid ____
Creatinine ____
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Chart 1: Initial Urinalysis
Observation/Test
Normal Value
Color
Pale yellow
Transparency
Clear (transparent)
Odor
Characteristic
Total Volume
Varies
Specific Gravity
1.001-1.030
[NaCl]
4-17g/L
Experimental Value
WBC
Nitrite
Protein (albumin)
Glucose
Ketone
Urobilinogen
Bilirubin
RBC
pH
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