Screening and assays

Question 1

screening tests are used on

Answer 1

those who appear healthy and aim to detect diseases at an early stage, before symptoms are noticeable

Question 2

positives of screening

Answer 2

• early diagnosis- better prognosis, cheaper treatment
• may help you stop habits which increase your risk
• could be preventative

Question 3

negatives of screening

Answer 3

• can be harmful e.g. Xray radiation

- can help you prepare your future

Question 4

no point in screening if

Answer 4

no treatment available after diagnosis

Question 5

assay

Answer 5

is a method to analyse or quantify a particular biomarker in a sample e.g. serum sodium level or the sequence of a gene
e.g. ELISA

Question 6

Outline Direct ELISA

Answer 6

1) antibody is adsorbed to well
2) patient sample is added and complementary binds to antibody
3) enzyme linked antibody specific for test antigen is added and binds to antigen- forming a SANDWICH
4) enzyme Substrat tis added and reaction produces a product that causes a visible colour change

Question 7

outline indirect ELISA

Answer 7

1) antigen is adsorbed to well
2) patient serum is added - complementary antibody binds to antigen
3) Enzyme- linked antibody- specific to primary antibody, is added and binds to bound antibody
4) enzyme substrate is added and retain produces a product that causes a visible colour change

Question 8

a test

Answer 8

is the use of a specific assay within a specific context e.g. for a particular disease, in a particular population or for a particular purpose

Question 9

a screen

Answer 9

tests which are used on those who appear healthy and aim to detect disease at a early stage, before symptoms ar noticeable