The ELISA Test
=
→ The linked immunosorbent LEUSAJ if patient has antibodies to
enzyme assay allows to see a
any
-
you
a certain
antigen or
any antigen to a certain antibody .
for infections for for
.
It can be used to test pathogenic ,
allergies and anything you can associate an
antibody
for .
'
In an ELISA test ,
an
antibody is used which has an
enzyme attached to An allergy is an inappropriate
of
it . This
enzyme can react with a substrate to
produce a coloured product reaction the immune
system
shouldn't
which causes the solution in the reaction vessel to
change colour .
to an
antigen that
If normally
there's colour
change it demonstrates that the
antigen trigger response
'
a or a .
,
tested
antibody of interest is present in the sample being .
of be from of the
-
The
quantity this
antigen 1 antibody can worked out the
intensity colour
change .
of ELISA
There two
types :
'
are
↳ Direct ELISA : uses
single antibody that is
testing for
complementary
a to the
antigen you a re .
↳ Indirect ELISA : uses two different antibodies
,4/1/44
Direct ELISA
I
§
1
Antigens from a patient sample are bound in a well plate .
2 detection to
A
antibody with attached is
complementary the antigen
.
an
enzyme
3 If the antigen is present ,
it will be immobilised on the inside surface of the well and the
detection antibody will bind to it .
4 washed out to
Well is remove
any
unbound antibody and a substrate is added .
5 A positive result (
antibody present
) causes
enzyme to react to the substrate to give
a colour
change .
4¥
Indirect ELISA
( Example below to see if patient has antibodies to HN virus )
""÷. .
,"
1 HIV is bound to the bottom of
antigen a well .
Well washed
2 Patient 's blood plasma is added .
HIV -
specific antibodies bind to
antigens . is
out to remove unbound antibodies .
HIV specific antibody
A secondary antibody attached to an enzyme is added
They bind to the -
3
. .
washed out
Well is again to remove
any unbound secondary antibody .
A substrate added
4 is which reacts with the enzyme attached to the secondary antibody and
product If solution HIV specific antibodies hence
produce a coloured .
changes colour, -
are present
is infected with HIV .
t colour change
"
-
-
antibody to
-
-
-
-
-
-
specific
antigen
-1N wash out
wash out
"
of
✓
h
HIV
of T T &
K
a
=p
✓
f antibody o
y
'
7 Y do
antigen specific to
antibody
secondary
or a is
antigen
• • so on .
i. Hiv qfaf af of ar N N
attached
•
• Be so • •
'
•
• •
f f
o so •
k f
a
⑨ • •
•
f f
a @ a
f h
• • •
or
with
enzyme ②
4 4
• • • •
41 • •
,
a
=
→ The linked immunosorbent LEUSAJ if patient has antibodies to
enzyme assay allows to see a
any
-
you
a certain
antigen or
any antigen to a certain antibody .
for infections for for
.
It can be used to test pathogenic ,
allergies and anything you can associate an
antibody
for .
'
In an ELISA test ,
an
antibody is used which has an
enzyme attached to An allergy is an inappropriate
of
it . This
enzyme can react with a substrate to
produce a coloured product reaction the immune
system
shouldn't
which causes the solution in the reaction vessel to
change colour .
to an
antigen that
If normally
there's colour
change it demonstrates that the
antigen trigger response
'
a or a .
,
tested
antibody of interest is present in the sample being .
of be from of the
-
The
quantity this
antigen 1 antibody can worked out the
intensity colour
change .
of ELISA
There two
types :
'
are
↳ Direct ELISA : uses
single antibody that is
testing for
complementary
a to the
antigen you a re .
↳ Indirect ELISA : uses two different antibodies
,4/1/44
Direct ELISA
I
§
1
Antigens from a patient sample are bound in a well plate .
2 detection to
A
antibody with attached is
complementary the antigen
.
an
enzyme
3 If the antigen is present ,
it will be immobilised on the inside surface of the well and the
detection antibody will bind to it .
4 washed out to
Well is remove
any
unbound antibody and a substrate is added .
5 A positive result (
antibody present
) causes
enzyme to react to the substrate to give
a colour
change .
4¥
Indirect ELISA
( Example below to see if patient has antibodies to HN virus )
""÷. .
,"
1 HIV is bound to the bottom of
antigen a well .
Well washed
2 Patient 's blood plasma is added .
HIV -
specific antibodies bind to
antigens . is
out to remove unbound antibodies .
HIV specific antibody
A secondary antibody attached to an enzyme is added
They bind to the -
3
. .
washed out
Well is again to remove
any unbound secondary antibody .
A substrate added
4 is which reacts with the enzyme attached to the secondary antibody and
product If solution HIV specific antibodies hence
produce a coloured .
changes colour, -
are present
is infected with HIV .
t colour change
"
-
-
antibody to
-
-
-
-
-
-
specific
antigen
-1N wash out
wash out
"
of
✓
h
HIV
of T T &
K
a
=p
✓
f antibody o
y
'
7 Y do
antigen specific to
antibody
secondary
or a is
antigen
• • so on .
i. Hiv qfaf af of ar N N
attached
•
• Be so • •
'
•
• •
f f
o so •
k f
a
⑨ • •
•
f f
a @ a
f h
• • •
or
with
enzyme ②
4 4
• • • •
41 • •
,
a
