Urine diagnosis 15.7

Question 1

Why is urine so important in diagnosis?

Answer 1

Urine contains many different chemicals that are breakdown products, things like salts, hormones etc…
If you have certain types of diseases, abnormal ranges of chemicals will appear in your urine

Question 2

Give two examples of diseases or illnesses that can be tested for using urine?

Answer 2

• Glucose in the urine indicated diabetes

- Creatinine in the urine indicates muscle damage

Question 3

What do pregnancy tests detect in the urine?

Answer 3

When a fetus is implanted into the uterus, the placenta starts to grow and produces a chemical called hCG. This is what is detected by the pregnancy test using monoclonal antibodies

Question 4

What was an effective way of testing for pregnancy in the past?

Answer 4

They injected urine into a frog and if the woman was pregnant, it would trigger egg production 12 hours after injection. The woman must’ve been pretty far along

Question 5

What are monoclonal antibodies and how are they made?

Answer 5

They are antibodies cloned from a single clone of cells and they target specific chemicals in the body. A mouse will be injected with the hCG. Its beta cells that make the required antibody are removed from its spleen and fused with myeloma which divides very rapidly. This produced a hybridoma and this reproduces rapidly, making millions of antibodies which are then collected and purified

Question 6

How does a pregnancy test work?

Answer 6

• The wick is soaked in urine passed in the morning which will have the highest levels of hCG
• The test contains the mobile monoclonal antibodies attached to a coloured bead and they will only bind to the hCG if the woman is pregnant and form a hCG antibody complex
• The urine is carried along with the test structure until it reaches a window
• When it reaches the first window, there are immobilised monoclonal antibodies that will only attach to the hCG antibody complex and these are arranged in a line or plus. If the woman is pregnant, this will appear in the first window
• The urine will pass into a second window where there are monoclonal antibodies that will bind to any mobile antibodies regardless of whether it has hCG or not, this shows the test is working
• If the woman is pregnant, both lines appear. if only one line, she’s not pregnant

Question 7

How do you use urine to test for anabolic steroids?

Answer 7

Anabolic steroids mimic the action of testosterone and stimulate the growth of muscles. This is excreted in the urine, so scientists can use gas chromatography and mass spectroscopy to analyse this. The urine sample is vapourised with a known sample and passed along a tube that will absorb the gases and analyse it to give a chromatogram which can then be analysed.

Question 8

How can you drug test using urine?

Answer 8

If a person has taken illegal drugs or alcohol, it can be tested for in the urine as the metabolites (breakdown products of the drugs) are filtered through the kidneys and stored in the bladder which means trace amounts can be found in the urine.
An immunoassay is first used which uses monoclonal antibodies to bind to the product of the drug. If this comes back positive, they use gas chromatography to analyse which drug it was