Unit 5 Flashcards
What does ELISA stand for
Enzyme linked immunosorbent assay
What is ELISA used for
Using antibodies and color change to identify concentration of antigens in a mixture
How does ELISA work
Antigens from a sample are coated on wells of plate and
these wells are filled with dilutions of patients serum.
If antibodies are present, they bind onto the bottom as they’re antigen specific, the enzyme is complementary to the substrate causing them to adhere to the unbound antibodies that are removed when the wells are
washed out.
A second solution is added with a 2nd antibody and wells
are washed again.
A solution of colorgenic enzyme substrate is added causing an enzyme substrate reaction.
Interaction of substrate with enzyme on the 2nd antibody generates a visible colour.
This is detected by a colour miter which shows us the amount of colour produced that
correlates with the concentration of the target analyse in the sample.
A calibration curve is
also used which shows us which
concentration of haemoglobin the patients sample is on.
The more
enzyme substrate
complexes present,
the more colour
change detected.
How might sensitivity affect ELISA
incorrect selection of enzymes and/or substrate may be added therefore this doesn’t allow us to produce a visible
reaction
An incorrect capture of antibody could result
in not allowing initial
adhesion of an
antigen.
This will
give the patient a
false negative result.
How might specificity affect ELISA
incorrect selection of
non reacting proteins may interfere leading to non-specific binding of other proteins in sample
Choosing a nonspecific enzyme
which attaches to other molecules besides the target
antibody will give a false positive result
how does haematology work
used to examine components in the blood like red blood cells, white blood cells, platelets and haemoglobin
a full blood count involves measuring these blood components per millilitre of blood.
the mean size of red blood cells and the haemoglobin content present is identified.
how does haematology work
used to diagnose or treat conditions that affect the blood. This allows identification of abnormalities for diseases which can be tested
what is turbidimetry
used to measure the intensity of transmitted light that is lost due to to scattering effect of particles suspended
how is the wavelength created
when light is passed through the filter
what is the cuvette used for
to hold the sample solution allowing light to pass through
what is an interfering agent
can be the imperfections in the cuvette such as dusts and solids from the atmosphere which can interfere causing human error and inaccuracies in the findings
