SBI4U–HomeostasisUnit
Name:________________________________
PEEINTHECUP,PLEASE:UrinalysisLabInvestigation
Asatechnologist,youareresponsibleforanalyzingurinesamplesfromvariousHumbersideteachers.Youwillbe
lookingatthefollowing:
• Initialqualitativeanalysis:colourandturbidity(appearance)
• UrineglucoselevelusingateststripandconductingaBenedict’sTest
• UrinepH,usingapHmeter(orpHpaper)
• Proteinanalysis,usingtheBiuretTest
• Yeasttest,usinghydrogenperoxide
• Ketonestest,usingateststrip
Allobservationsaretoberecordedinatable.
Analysis:
Inanalyzingyourresultsyoushouldconsiderthefollowing:
• Researchwhatthenormallevelsof:urineglucoseconcentrations,urinepH,protein,ketonesandyeast
• Comparethetwosamplestothenormalvalues
• Determinewhichofyoursamples,ifany,resultsareabnormal.Makeadiagnosisandsuggestacourseof
furthertests
• Statethetreatmentforthepatientwithanabnormalsample(s).
• Yourreportshouldalsoaddresstheunderlyingcauseoftheabnormaltestresult(s)withspecificreference
to kidney function. Also, indicate what other systems, if any, in addition to the urinary system might be
involvedintheetiologyofthedisease.
Youwillbewritingthisreportintheformofaone-pagehandoutthatcanbedistributedtotheclass.Yourreport
shouldincludethefollowing:
• Atableofobservations
• Analysisofpatientsample(s)(asoutlinedabove)
• ReferencesinAPAformat
Herearesomeofthetoolsyoucanuse:
Biuret reagent can be used to identify proteins. It reacts with the peptide bonds joining amino acids
together,producingcolourchangesfromblue,indicatingnoprotein,topinkorpurple.
Benedict’ssolutioncanbeusedtoidentifysugars.Inthisinvestigation,Benedict’ssolutionwillbeusedto
detectglucoseintheurine.ThecolourchartinTable1summarizesthequantitativeresultsobtainedwhen
reducingsugars,suchasglucose,reactingwithBenedict’ssolution.
q
q
Table 1
Colour of
Benedict’s solution
Approximate %
of sugar
Colour of
Biurets
Protein in
urine
Ketones
in urine
pH
value
negative
blue
negative
negative
5
light green
0.5%–1.0%
pink/purple
positive
positive
6
green to yellow
1.0%–1.5%
7
orange
1.5%–2.0%
8
+2.0%
9
blue / purple
red to red-brown
Safety Prequations
Safetygogglesmustbewornfortheentirelaboratory.Allreagentswillstain.
Benedict’ssolutionistoxicandcorrosive.Biuretreagentistoxic.Avoidskinandeyecontact.
Washallsplashesoffyourskinandclothingthoroughly.Ifyougetanychemicalinyoureye,
rinseyoureyeforatleast15minutesandinformyourteacher.
Materials
•
•
•
•
•
•
safetygoggles
gloves
2urinesamples,labeled
test-tubeclamp
pen
testtuberack
• Benedict’ssolution(insmall
dropperbottle)
• Beakers
• 2smalltesttubes
• glucosereagentstrips
• ketoneteststrips
• hotwaterbath
• test-tubebrush
• Biuretreagent(insmall
dropperbottle)
• UniversalpHpaper
Procedure
1. Obtaintwounknownsamplesfromyourteacher.
2. Labeltwotesttubestheunknownsamplenumbers.Place1dropper-fullofurineintoeachlabeledtesttube.
3. Observeandrecordthecolourandappearanceoftheurine.
4. Add1dropper-fullofBenedict’ssolutiontoeachtesttubeand,usingatest-tubeclamp,placethetesttubes
inahotwaterbath(approximately80°C–donotletitboil).
5. Observefor6minutes.TURNOFFTHEHEATSOURCE.Leavehotplateandwaterbathtocoolwhendone.
(a) RecordanycolourchangesinTable2.
(b) UseTable1onthepreviouspagetoidentifythevaluesforeachsample.Recordthevaluesandcolour
inTable2.
6. Forthesamplesthattestpositiveforglucose(Benedict’stest),usetheglucosereagentstripstodetermine
theamountofglucose.Youshouldusethebeakersample.Recordyourresultsinthetable,includeyourunits.
7. Washeachofthetesttubesusingthetesttubebrushbeforebeginningtheproteintest.
8. Place1dropper-fullofurineintoeachlabeledtesttube.
9. Add1dropper-fullofBiuret’ssolutiontoeachtesttube.Tapthetesttubetomixthecontents.
10. UseTable1(onpreviouspage)toidentifythevaluesforeachsample.RecordthevaluesandcolourinTable2.
11. Place1dropper-fullofurineintoeachlabeledtesttube.
12. Addonedropper-fullofhydrogenperoxidetoconducttheyeasttest.Recordthepresenceofanybubblesin
Table2.Thepresenceofbubblesindicatesthepresenceofyeast.
13. UsetheuniversalpHpapertodeterminethepHofeachsampleinthebeaker.Recordyourresults.
14. Usetheketoneteststriptodetermineifthereareketonespresentinthesample.Recordyourresults.
15. Cleanupyourworkspace.Disposeofallchemicalsasdirectedbyyourteacher
16. Washyourhandsthoroughly.
TableofObservations/Results(Table2)
Observation
Colour
Clarity
(transparent
orcloudy)
Glucose
(Benedict’s)
Results
Glucose
(Diastix)
Results
Protein
(Buiret’s)
Results
YeastResults
pH
Ketones
Sample#________
Sample#________