Immunophenotyping is a technique used to study the protein expressed by cells. This technique is commonly used in basic science research and laboratory diagnostic purpose. This can be done on tissue section (fresh or fixed tissue),
cell suspension, etc. An example is the detection of
tumor markers, such as in the
diagnosis
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine "cause and effect". In systems enginee ...
of
leukemia
Leukemia ( also spelled leukaemia and pronounced ) is a group of blood cancers that usually begin in the bone marrow and result in high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or ...
. It involves the labelling of
white blood cell
White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from mult ...
s with
antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of th ...
directed against surface
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
s on their membrane. By choosing appropriate antibodies, the differentiation of
leukemic cells can be accurately determined. The labelled cells are processed in a
flow cytometer, a laser-based instrument capable of analyzing thousands of cells per second. The whole procedure can be performed on cells from the
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in th ...
,
bone marrow
Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of hematopoietic ...
or
spinal fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of th ...
in a matter of a few hours.
An example of information provided through Immunophenotyping:
"The flow cytometric immunophenotyping report indicated the malignant cells were positive for CD19, CD10, dimCD20, CD45, HLA-DR, and λ immunoglobulin light chain. There was no coexpression of CD5 or CD23 by the monoclonal
B-cell
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted ...
population."
Immunophenotyping is a very common flow cytometry test in which fluorophore-conjugated antibodies are used as probes for staining target cells with high avidity and affinity. This technique allows rapid and easy phenotyping of each cell line in a heterogeneous sample according to the presence or absence of a protein combination. Thus, visibility increases in complex samples.
References
External links
British Society for Haematology guidelinesaccessed July 31, 2006
* {{MeshName, Immunophenotyping
Flow cytometry
Hematology