Biomedical Engineering Reference
In-Depth Information
represents an extremely valuable fluorescent dye for immunological stud-
ies, allowing lymphocyte proliferation, migration, and positioning to be
simultaneously monitored. By the use of fluorescent antibodies against
different lymphocyte cell surface markers, it is also possible to follow the
proliferation behavior of different lymphocyte subsets. In addition, un-
like other methods, CFSE-labeled viable cells can be recovered for further
analysis.
Chemotaxis: A phenomenon whereby cells, bacteria, and other single-cell
or multicellular organisms direct their movements according to the con-
centration gradients of selected chemicals in their environment. Positive
chemotaxis occurs if the movement is toward a higher concentration of
the chemical in question, which is therefore called a chemoattractor. Con-
versely, negative chemotaxis occurs if the movement is in the opposite
direction, and the relative chemical substance is called chemorepellent.
Such chemical-induced directional migration is important for bacteria to
find food (for example, glucose), or to flee from poisons (for example,
phenol). In multicellular organisms, chemotaxis is critical to early devel-
opment (e.g., movement of sperm toward the egg during fertilization) and
subsequent phases of development (e.g., migration of neurons or lympho-
cytes) as well as in normal function. In addition, it has been recognized
that mechanisms that allow chemotaxis in animals can be subverted dur-
ing cancer metastasis.
Compartmentalization: Representation of a simulating individual through
a set of discrete objects, reproducing its specific subcompartments.
Contact inhibition: Inhibition of cell locomotion due to the overexpression
of cell{cell adhesive contacts in regions with high cellular density.
Dulbecco's minimal essential medium (DMEM): A cell culture medium
used to maintain cells in tissue culture. It contains vitamins (folic acid,
nicotinamide, riboflavin), salts (calcium chloride, potassium chloride,
magnesium sulfate, sodium chloride, and monosodium phosphate), amino
acids, glucose, iron, and phenol red. DMEM is suitable for most types
of cells, including human, monkey, hamster, rat, mouse, chicken, and fish
cells.
Fetal calf serum (FCS, or fetal bovine serum): The portion of plasma
remaining after coagulation of blood, as during this process the plasma
protein fibrinogen is converted to fibrin and remains behind in the clot.
FCS is the most widely used serum supplement for the in vitro cell culture
of eukaryotic cells. This is because it has a very low level of antibodies and
containing more growth factors, allowing for versatility in many different
cell culture applications.
Fingers: Tongues of cells protruding from the main tumor mass, a conse-
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