Answer:
Your answer will be the Hindbrain.
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Answer: For detection and confirmation of HIV antibodies in blood samples.
Explanation: As the name implies ELISA( Enzyme-linked immunosorbent assay) is the first test widely used for determining the presence of HIV in a person's serum because of its high sensitivity. In an ELISA, a person's serum is diluted 400 times and applied to a plate to which HIV antigens are attached. If antibodies to HIV are present in the serum, they may bind to these HIV antigens. The plate is then washed to remove all other components of the serum. A specially prepared "secondary antibody" (an antibody that binds to other antibodies) is then applied to the plate, followed by another wash. This secondary antibody is chemically linked in advance to an enzyme.
Thus, the plate will contain enzyme in proportion to the amount of secondary antibody bound to the plate. A substrate for the enzyme is applied, and catalysis by the enzyme leads to a change in color or fluorescence. ELISA results are reported as a number; the most controversial aspect of this test is determining the "cut-off" point between a positive and a negative result. A cut-off point may be determined by comparing it with a known standard. Unknown samples that generate a stronger signal than the known or control sample or are called "positive" while those that generate weaker signal are "negative".
Homeostasis is the regulation of internal body conditions such as temperature, sugar levels in blood, salt content etc. Without it many functions would become non-functional. If you take temperature for example without the control of our internal body temperature many metabolic reactions (enzyme-controlled reactions) would stop/ slow down. If the temp gets too high the enzymes denature and you wouldn't get an enzyme-substrate complexes forming. If the temp is too low the enzymes have a low kinetic energy and so don't collide with the substrate as much as at normal body temp. pH has similar affect but a change in pH will always denature enzymes.