Antibodies in Medicine

Question 1

Monoclonal antibodies

Answer 1

antibodies produced from a single group of genetically identical B cells

Question 2

MABS to target cancer cells

Answer 2

ONLY Cancer cells have tumour markers
attach anti cancer drugs to antibodies
antibodies come into contact with cancer cells and bind to tumour markers
drug only accumulates where cancer cells present
side effects of antibody based drug are lower than other drugs as they target specific cells

Question 3

MABS for medical diagnosis

Answer 3

i.e. pregnancy tests
application area contains hcG antibodies bound to blue coloured bead
urine applied - any hCG present will bind to antibody forming antigen-antibody complex
Test strip contains immobilised antibodies
hCG present = strip goes blue as immobilised antibody binds to hcG
hCG antibody complexes with blue beads attached become concentrated
no hCG = beads pass through test strip = test strip doesn’t turn blue

Question 4

ELISA

Answer 4

enzyme linked immunosorbent assay
shows if patient has antibodies to certain antigen and vice versa
tests for pathogenic infections for allergies and other antibody required things

Question 5

how ELISA works ( basic)

Answer 5

antibody with enzyme attached to it
enzyme specific substrate can react with enzyme to produce a coloured product
colour change demonstrates that the antigen/antibody of interest is present in tested sample
sometimes quantity of antigen/body can be worked out from intensity of colour change

Question 6

Indirect ELISA

Answer 6

uses two different antibodies

Question 7

Direct ELISA

Answer 7

uses a single antibody complementary to desired antigen

Question 8

ELISA to test for HIV

Answer 8

HIV antigen bound to bottom of a well
sample of patients blood added to well
HIV specific antibodies bind to antigen
well is washed to remove unbound antibodies
secondary antibody with specific enzyme added to the well
well washed again for unbound 2y antibodies
solution added to well containing substrate (complementary to enzyme)
if colour change occurs, patient has HIV specific antibodies
TF patient is HIV+

Question 9

why wash?

Answer 9

could affect results i.e. unbound secondary antibodies could cause the test to appear positive when no HIV antibodies present

Question 10

Ethical issues

Answer 10

Animals used to produce cells which then produce monoclonal antibodies (i.e. animals given diseases to produce desired antibody)