COURSE: MASTER OF SCIENCE MEDICAL MICROBIOLOGY
UNIT: SEROLOGY AND IMMUNOLOGY
ASSESMENT TEST
SCHOOL: PURE AND APPLIED SCIENCE
Answer all questions each 25 Marks.
1 . Discuss the various serological techniques used in modern diagnostics, including
a ) ELISA
The Enzyme-Linked Immunosorbent Assay (ELISA) is a laboratory technique used to measure
particular group of antibodies or antigens from serum and it is commonly used due to accuracy
, and speed. ELISA functions majorly through the antigen-antibody binding where either of the
component is attached to a plate and using the enzyme labelled antibodies binding takes place to
produce a color change depending on the antigen or antibody present.
There are different types of ELISA test including: Sandwich, competitive, direct and indirect.
The Sandwich ELISA is widely used to quantify antigens between two specific antibodies where
the antigen finally binds to the capture antibody. Competitive determines the antigen
concentration via competition between the reference and sample antigen for the enzyme-labeled
antibodies. Direct Elisa uses a single primary antibody to detect antigen while Indirect ELISA
uses a primary antibody which is later followed by a secondary enzyme-linked antibody.
The application of ELISA during diagnosis can be used to detect different diseases such as HIV,
Hepatitis, Covid -19. It can also be used for pregnancy and allergy testing. The use of ELISA is
very specific and reliable thus producing accurate results.
b) Western blot
Western blot also known as immunoblotting is a serological diagnostic procedure used for
detection of certain proteins from a sample using antigen-antibody reaction. This technique
enables detection and general analysis of specific proteins from a mixture with visible color
change usually dark caused by the reaction. This makes it possible to confirm the presence of
certain infections within a given sample.
The procedure involves extraction of proteins from a sample followed by gel electrophoresis
which separates the proteins based on their sizes. This is followed by transformation of the
already separated proteins into a membrane where it is treating with a blocking solution whose
function is to prevent non-specific binding. Addition of primary antibody enables binding with
UNIT: SEROLOGY AND IMMUNOLOGY
ASSESMENT TEST
SCHOOL: PURE AND APPLIED SCIENCE
Answer all questions each 25 Marks.
1 . Discuss the various serological techniques used in modern diagnostics, including
a ) ELISA
The Enzyme-Linked Immunosorbent Assay (ELISA) is a laboratory technique used to measure
particular group of antibodies or antigens from serum and it is commonly used due to accuracy
, and speed. ELISA functions majorly through the antigen-antibody binding where either of the
component is attached to a plate and using the enzyme labelled antibodies binding takes place to
produce a color change depending on the antigen or antibody present.
There are different types of ELISA test including: Sandwich, competitive, direct and indirect.
The Sandwich ELISA is widely used to quantify antigens between two specific antibodies where
the antigen finally binds to the capture antibody. Competitive determines the antigen
concentration via competition between the reference and sample antigen for the enzyme-labeled
antibodies. Direct Elisa uses a single primary antibody to detect antigen while Indirect ELISA
uses a primary antibody which is later followed by a secondary enzyme-linked antibody.
The application of ELISA during diagnosis can be used to detect different diseases such as HIV,
Hepatitis, Covid -19. It can also be used for pregnancy and allergy testing. The use of ELISA is
very specific and reliable thus producing accurate results.
b) Western blot
Western blot also known as immunoblotting is a serological diagnostic procedure used for
detection of certain proteins from a sample using antigen-antibody reaction. This technique
enables detection and general analysis of specific proteins from a mixture with visible color
change usually dark caused by the reaction. This makes it possible to confirm the presence of
certain infections within a given sample.
The procedure involves extraction of proteins from a sample followed by gel electrophoresis
which separates the proteins based on their sizes. This is followed by transformation of the
already separated proteins into a membrane where it is treating with a blocking solution whose
function is to prevent non-specific binding. Addition of primary antibody enables binding with
