Monoclonal Antibodies

Question 1

How can a monoclonal antibody can be developed and used to detect an STI using a urine sample?

Answer 1

Isolate an antigen from the pathogen which causes the STI. Inject the antigen into a mouse. Collect lymphocytes producing an antibody to the STI antigen. Fuse the B-lymphocyte with a myeloma cell, producing a hybridoma cell. Hybridoma cells produce a monoclonal antibody against the antigen of the STI. Attach the monoclonal antibody to colored bead/indicator and incorporate into a test strip.

Question 2

Monoclonal antibody process

Answer 2

Lymphocytes produce desired antibodies but don’t divide quickly. Inject a mouse with the antigen so the mouse develops an immune response, producing antibodies specific to the antigen. The lymphocytes that produce these antibodies are derived from the spleen of the mouse and are fused with myeloma cells, producing hybridoma cells. The hybridoma cells divide rapidly and produce an army of antibodies specifically shaped to bind to the antigen. Collect and purify the monoclonal antibodies.

Question 3

Benefits of monoclonal antibodies

Answer 3

Specific (attach only to the toxic antigen so won’t effect healthy cells)

Question 4

Disadvantages of monoclonal antibodies

Answer 4

-Expensive
-Can cause side effects or rejection as they are produced from mice

Question 5

Monoclonal antibodies in pregnancy tests

Answer 5

The pregnancy hormone HCG is excreted in urine. Attach the monoclonal antibody specific to HCG to colored bead and incorporate into a test strip. When urinated on, if urine contains HCG it will bind to the antibodies on the coloured beads which, when flowing over the test strip, the HCG they are carrying binds to the fixed antibodies on the test strip, sticking them in place and making the pregnancy test appear with a coloured line for positive.