Antibodies in Medicine Flashcards
What are monoclonal antibodies used for?
to target medication to specific cell types by attaching a therapeutic drug to an antibody, pregnancy testing and medical diagnosis by identifying proteins or antigen presence using the ELISA test
What is Radioimmunotherapy?
allows doctors to target radiation to specific sites
inks radioactive atoms to monoclonal antibodies that deliver the radioactivity by seeking out and latching onto proteins found on cancer cells
concentrate radiation to tumour sites
How do pregnancy tests work?
Antibodies complementary to hCG protein are bound to a coloured bead
hCG in urine binds to antibodies
Urine moves up the strip carring beads
Immobilised antibodies which bind to hCG create first ‘blue line’
Immobilised antibodies which bind to coloured beads create second ‘blue line’ if hCG is present
What is the ELISA test?
Enzyme Linked Immunosorbent Assay
used to test for the presence of any antigen or antibody
How does an ELISA test work?
antibody is bound to enzyme, this enzyme reacts with a substrate to produce a colour change. The antibody will be complementary and bind to the antigen or an antibody the test is designed to detect. There is a washing step which will remove any unbound antibodies so the more antigen there is in the sample, the more colour changes there will be because the more enzymes will be present to react with the substrate
What is the Direct ELISA test?
involves one antibody binding to one antigen, used to look for the presence of an antigen in a sample
What is the Indirect ELISA test?
uses multiple antibodies
How does the Indirect ELISA test work?
antigens are immobilised and the sample being checked for antibodies is added
a wash step occurs before a second antibody is added which will bind to the antibodies attached to the antigens if present/ This antibody has the enzyme bound that will change colour
What are the disadvantages of Indirect ELISA test?
Be more sensitive than direct detection methods
Risk of cross- reactivity with the antigen, which could cause higher background readings
Take longer due to the extra step
