immunoassay essay plan

Question 1

what you gonna write in your intro

Answer 1

• immunoassay is a specific reaction between antigen + antibody = immune complex
• amount of complex = amount of analyte (substnace of interest)

Question 2

what can we write for competitve immunoassay

Answer 2

analyte competes with labelled analyte for antibody binding site

signal indirectly proportional to amount of analyte

Question 3

what can we write for non competitive:

Answer 3

analyte binds to antibodies

labelled antibodies bind to analyte to form sandwich

directly proportional signal to analyet

Question 4

radioactive label

Answer 4

radioisotope - tracer

Isotope = unstable atom variant => stable = energy emitted (Geiger counter)
decay of tracer => gamma/beta particles

phased out for safety

Question 5

methods of detection: enzyme label examples what they do

Answer 5

coloured dye, flourescence, luminscence

Produce product molecules that are detectable and enhance sensitivity

Question 6

coloured dye (pregnancy)

Answer 6

pregnancy test and lateral flow

hCG binds to antibodies that have coloured dye

pad absorbs urine - hcg present = pregnant

Question 7

fluorescnece

Answer 7

e.g. flow cytometry

flourophore absorbs light at short wavelegnth and remits at long wavelength

detected by fluorimeter

Question 8

chemiluminescnece

Answer 8

ab or ag labelled

substrate breaks down

light emits - detected by luminometer

Question 9

conclusion - why useful?

Answer 9

specific

sensitive (small amount can be measured)

large scale

automated

Question 10

conclusion - used by what?

Answer 10

urine albumin

hormones

drug abuse

tumour markers