Fructose is the energy source for sperm motility. A positive fructose is considered normal. Azoospermia and fructose negative results may indicate an absence or obstruction of seminal vesicles / vas deferens. This test is typically conducted as part of a male fertility evaluation to assess the presence and quantity of fructose in semen, which can provide insights into the function of the seminal vesicles, the glands responsible for producing seminal fluid.