<span>The most crucial principle of ELISA (enzyme-linked immunosorbent assay) is a highly specific antibody-antigen interaction.</span>
ELISA is a biochemical technique used to detect the presence of an antibody or an antigen in the biological sample. Simply described, in an ELISA, an antigen is immobilized on a solid surface and then a specific antibody is applied over the surface so that it can bind to the antigen. The antibody is usually linked to an enzyme, and in the final step, a substrate for that enzyme is added. The enzyme can convert it to some detectable signal, most commonly a color change. <span>Medical usage of ELISA is in the diagnosis of HIV infection, pregnancy tests, measurement of cytokines…</span>
When an atom transfers/ gains a valence electron, it gains either a positive or negative charge. in the Proces, becoming an ion. because of the negative/positive charge the two ions are now attracted to each other.
The amount of sagebrush would increase, which would lead to an increased population of jackrabbits, as sagebrush their food source. As the amount of jackrabbits increase, it gets easier for coyotes to hunt for them which in return, increases their survival rate/population.
Answer and Explanation:
12. The water has a lower osmotic pressure than the cell sap of the root hairs. Due to the osmotic difference water is drawn by osmosis across the cell wall and cell membrane into root hairs. Water moves by osmosis into adjacent cortex cells and their osmotic pressure is lowered drawing water by osmosis. Water passes to the successive cortex cells and through the endodermis to the xylem vessels. At the leaves, the xylem passes into the petiole and then into the veins of the leaf. Water leaves the veins and enters the cells of the spongy and palisade layers.
13. Food and other manufactured material are translocated by the phloem. They enter the sieve elements through plasmodesmata connecting them to adjacent companion cells which are sites of high metabolic activity. The manufactured food are translocated through sieve tube along the cytoplasmic strands.