3.2 Monoclonal antibodies (Triple, Higher)

Question 1

What are monoclonal antibodies (mAbs)?

Answer 1

● Antibodies that are clones from one parent cell

● Specific to one type of antigen

Question 2

Describe how monoclonal antibodies are produced?

Answer 2

1. Specific antigen injected into an animal (e.g. mouse)
2. B-lymphocytes producing complementary antibodies extracted
3. B-lymphocytes fuse with myeloma cells to form hybridoma cells - these cells can divide and produce monoclonal antibodies
4. Hybridoma cells are cultures
5. Monoclonal antibodies are collected and purified

Question 3

Outline the uses of monoclonal antibodies

Answer 3

● Detection of pathogens

● Location of cancer cells and blood clots

● Treatment of cancer

● Used in pregnancy test kits

Question 4

What are myeloma cells?

Answer 4

A type of tumour cell

Question 5

What do pregnancy kits test for?

Answer 5

hCG in urine

Question 6

What does a pregnancy test consist of?

Answer 6

A stick containing monoclonal antibodies (mAbs) specific to hCG:

● mAbs attached to a blue bead (free to move)

● mAbs fixed to the test stick

Question 7

Describe what happens to the test stick if a woman is pregnant

Answer 7

1. hCG in urine binds to mAbs attached to a blue bead
2. mAbs with hCG diffuse up the stick
3. mAbs fixed to the stick bind to the hCG
4. Blue line forms

Question 8

Describe what happens to the test stick if a woman is not pregnant

Answer 8

No hCG in urine so a blue line is not formed

Question 9

What is the advantage of using monoclonal antibodies to test for pathogens?

Answer 9

● Specific to one particular antigen

● Very accurate

● Quick results

Question 10

Why can monoclonal antibodies be used to target cancer cells?

Answer 10

● Cancer cells have specific antigens called ‘tumour
markers’ on their
membranes

● mAbs are specific to one type of antigen so can be
targeted to ‘tumour
markers’ without damaging other cells

Question 11

Describe how monoclonal antibodies can be used to diagnose cancer

Answer 11

1. mAbs tagged to a
   radioactive substance
2. mAbs injected to a patient’s bloodstream
3. mAbs bind to ‘tumour markers’ on cancer cells
4. Emitted radiation is detected using a specialised scanner enabling doctors to
   determine the location of cancer cells

Question 12

How can monoclonal antibodies be used to target drugs to cancer cells?

Answer 12

1. mAbs attached to an anti-cancer drug
2. mAbs injected into the patient’s bloodstream
3. mAbs bind to ‘tumour markers’ on cancer cells
4. Anti-cancer drug destroys cancer cells

Question 13

Why are cancer treatments that use monoclonal antibodies favoured over traditional treatments?

Answer 13

● Radiotherapy and chemotherapy target rapidly dividing cells

● Healthy cells (e.g. hair follicle cells, bone marrow cells) are damaged as a consequence, producing unpleasant side effects

● mAbs only target cancer cells, reducing damage to normal cells

Question 14

How can monoclonal antibodies be used to locate blood clots?

Answer 14

1. mAbs tagged to a radioactive substance
2. mAbs target and bind to a specific protein in blood clots
3. Radiation emitted by mAbs is detected, enabling the location of blood clots to be identified