Legal s Test
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Transcript of Legal s Test
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D. KETONE BODIELEGAL'S TESTGroup III
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INTRODUCTION
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PROCEDURES
1)Place about 1.0 mL of the normal urine sample and 1.0 mL ofabnormal urine sample in separate test tubes.
2)Add enough NaOH solution to render it slightly alkaline to
litmus paper.
3)Add a few drops of sodium nitroprusside solution and a few
drops of glacial acetic acid.
4)Observe the resulting change in color of the solution. Record
as positive or negative. Apurple or violet-red colorindicates
acetone. Alcohol or acetic acid and di-acetic acid also appear
red.
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RESULTS:
Normal Urine(-)
Red color
Abnormal Urine(+)
Violet-red color
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pH
A urine pH level test is a test that analyzes the acidity or alkalinity ofa urine sample.
pH of normal random sample ranges from 4.5-8.0
May indicate possibility of kidney stones
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Study Questions 1. Why are Ketone bodies not normally detected in urine?
Fats and CHO metabolism
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2. Name the 3 ketone bodies appearing in urine and the 3 ca
ketosuria.
Acetone
Acetoacetic acid(AcAc)
beta-hydroxybutyric acid(3HB)
Causes: Metabolic abnormalities
Dietary conditions
Conditions in which metabolism is increased
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3. What is the chief source of ketone bodies?
Chief source: liver
Ketone bodies are produced by the liver and used peripherally as an energywhen glucose is not readily available.
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4. What are the decomposition products of the urine test for ketone
ACETONE will decompose into isobutylene, carbon dioxide and water
BUTYRIC ACID will decompose into propylene, carbon monoxide and wat
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5. Discuss the principle of sodium nitroprusside reaction, in
sensitivity and possible causes of interference.
Nitroprusside reaction is a chemical test used for detecting the p
of free thiol groups of cysteine in proteins. Acetoacetic acid in an medium reacts with sodium nitroprusside to produce aPURPLE
The test does not measure beta-hydroxyutyric acid and is only
sensitive to acetone when glycine is also present; however, in as m
these compounds are derived from acetocetic acid, their presence
assumed and it is necessary to perform individual test.
In the interference, there is a false-positive and false-negative.
False-positive: Phthalein dyes, Highly pigmented red urine, Le
Medications containing free sulfhydryl groups.
False-negative: Improperly preserved specimen
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6. If the patient is on a low-carbohydrate diet, what advice who
give him/her if a positive result was obtained?
The ketones that form as a normal product of fat burning and
loss are nothing to be concerned about because they are
burned for energy by the body, and any excess are passed oubody in the urine.
For people with Type 1 diabetes, however, having measurableamounts of ketones in the urine (or blood) is cause for concern.
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7. Compare the principle and reaction involved in this test with t
the dipstick test for ketone bodies.
Legals test Detects ketone specifically acetone
An alkaline buffer is mixed with sodium nitroprusside, which gives a purple or violet-red colo
product by a reaction with acetone.
Urine dipstickAplastic strip isused, which contains pads that have incorporated within them the reagents
chemical reactions for the detection of a number of urine constituents. It is less sensitive towards acetone. The colour change is to shades of violet.
The comparison colour correspond approximately to acetoacetic acid.