Urine Samples and Pregnancy Tests

Question 1

Why can we use urine samples to detect things?

Answer 1

Molecules with a RMM of less than 69,000 can leave glomerulus and enter nephron so unless reabsorbed will stay in the filtrate and enter urine

Question 2

What can we diagnose by using urine samples?

Answer 2

-Diabetes
-Hypertension (High Blood Pressure)
-Pregnancy
-Anabolic Steroid Use in Athletes
-Use of Recreational Drugs

Question 3

Diabetes

Answer 3

-Have too much glucose in blood meaning more glucose than normal enters nephron and not all can be reabsorbed by PCT so enters the urine
-Test for glucose using Benedict’s Test or Test Strips

Question 4

Hypertension

Answer 4

If BP is too high, proteins can be forced through and can damage the basement membrane or epithelium of Bowman’s Capsule and enter the nephron and urine

Question 5

Pregnancy

Answer 5

When embryo implants in uterus lining, it produces a hormone called human chorionic gonadotrphin (hCH) which has a RMM of 36,700 so can leave blood and enter nephron and urine
-Detected using pregnancy tests

Question 6

Anabolic Steroids in Athletes

Answer 6

-They stimulate protein synthesis within cells (esp.
muscle cells) so are used to increase performance but they can cause liver damage and are seen to give athletes an unfair advantage so are banned in sports.
-Detected using gas chromatography/mass spectrometry

Question 7

Gas Chromatography

Answer 7

-Urine sample is vaporised and passed through a column containing a polymer.
-Different substances move through column at different so the substances in the urine samples are separated out.
-Mass spectrometer is then used

Question 8

Mass Spectrometery

Answer 8

-Converts them into ions which are then separated depending on their mass or charge
-Results are then analysed by a computer and compared with the results of known substances to identify what substances are in the urine

Question 9

Recreational Drugs

Answer 9

-Test strips which contain monoclonal antibodies
-If drugs/breakdown products of a drug are present, a colour change will occur
-If a positive result is found, a urine sample is sent off for analysis to determine what drugs have been used.
-Done by gas chromatography and mass spectrometery

Question 10

What tests work the same way as pregnancy tests?

Answer 10

Covid tests

Question 11

What are the 3 zones in a pregnancy test?

Answer 11

-Reaction
-Results
-Control

Question 12

Reaction Zone

Answer 12

Where you wee

Question 13

Results Zone

Answer 13

Pregnant or not

Question 14

Control Zone

Answer 14

Has the test worked?

Question 15

What is the first step of pregnancy tests?

Answer 15

Mobile hCG MAB’s (monoclondal antibodies) bind to hCG if present

Question 16

What are hCG MAB’s tagged with?

Answer 16

A blue dye

Question 17

What is the second step of pregnancy tests?

Answer 17

If hCG was present, mobile hCG MAB’s with hCG will bind to immobilised hCG MAB’s in results zone and a blue line will form if pregnant

Question 18

What is the third step of pregnancy tests?

Answer 18

Rest of mobile hCG MAB’s will move to control zone and bind to immobilised hCG MAB MAB’s (whether hCG was present or not) and another blue line will form to show MAB’s move along test strip