For most children, the National Heart, Lung, and Blood Institute recommends one cholesterol screening test between the ages of 9 and 11, and another cholesterol screening test between the ages of 17 and 21.
Wiktionary (0.00 / 0 votes) Rate this definition: fixation (Noun). The act of fixing, or the state of being fixed or fixated. fixation (Noun). The act of uniting chemically with a solid substance or in a solid form; reduction to a non-volatile condition; -- said of gaseous elements. fixation (Noun). The act or process of ceasing to be fluid and becoming firm.
Fresh tissue samples must be preserved for future examination. This process is called fixation, and the resulting specimen is described as fixed. Boiling an egg and pickling a cucumber represent examples of fixation, in which heat or chemistry stabilizes the organic materials.