31. The azide-tagged protein is then labeled with cyclooctyne-fluorophore conjugate to yield a fluorescently labeled protein. 32. They are labeled at their reducing ends with a fluorescent label ( i . e . a fluorophore ). 33. Therefore, the fluorophore used, the length of the linker, and its position must be carefully selected. 34. Light is directed at the fluorophore which absorbs energy and then re-emits light at a longer wavelength. 35. The technique relies on a distant-dependent transfer of energy from a donor fluorophore to an acceptor dye. 36. On one end of the pin is a chemical unit called a fluorophore , which can absorb and emit light. 37. When these two units touch _ when the clothespin is closed _ the quencher keeps the fluorophore from lighting up. 38. The antibodies are then coupled chemically to a fluorophore and used to trace the proteins in the cells under study. 39. Reabsorption happens because another molecule or part of a macromolecule absorbs at the wavelengths at which the fluorophore emits radiation. 40. If this is the case, some or all of the photons emitted by the fluorophore may be absorbed again.
