14. Home pregnancy test kit:-
• It contain HCG(human chorionic gonadotropin) coated latex particle
& Ab to the HCG
• The addition of urine of pregnant woman , which contain HCG
inhibited the agglutination of the latex particle upon addition of
anti-HCG Ab
• The absence of agglutination indicate pregnancy
15.
16.
17. To determination of individual consuming illegal drugs:-
• To check individual consuming certain drugs like cocaine or heroin
Urine or blood
sample
Ab specific
for drug
Drug coated
RBCs
RBCs not
Agglutinated
Person consume
the drug
18. In brief:-
To determine viral exposer or not
Determination of particular drug in
body
In pregnancy kit
19.
20. • For determination of Ab in sample
• Generally used in AIDS , for Ab against HIV within 6 weeks
of infection
• Envelope & core protein of HIV used as Ag
26. Principle:-
• Competitive binding of radiolabeled Ag & unlabeled Ag to a high
affinity Ab
• The labeled Ag is mixed with Ab at a concentration that saturates
the Ag binding sites of Ab
27.
28. Procedure:-
Assay mixture
(labeled Ag + Ab)
Test sample
(unlabeled Ag)
Compete with
labeled Ag
Decrease amount
of labeled Ag
bound to Ab
Precipitation of
Ag –Ab complex
29. Radioactivity of
precipitate will be
measured
Standard curve can be generated using unlabeled Ag of known
concentration & from this plot amount of Ag in test can be determine
30. Several methods for separating bound Ag from free Ag:-
1) Precipitation of Ag –Ab complex with secondary anti –isotype
antiserum e.g. Ag –Ab (rabbit IgG ) then goat anti-rabbit IgG will
bind to rabbit IgG Ab & precipitate the complex
2) Protein A of S. aureus has high affinity for IgG. If Ag –Ab (IgG) then
it will precipitated by formalin killed S. aureus.
3) Solid phase RIA:
Ab is covalently crosslinked with sepharose beads .The amount of
radiolabel Ag can be measured after beads have been centrifuge &
washed
Ab can be immobilized on polystyrene or PVC wells & amount of
free labeled Ag can be determine in radiation counter
