An association football (soccer) match is presided over by a referee, whom the Laws of the Game give full authority to enforce the Laws of the Game in connection with the match to which he has been appointed (Law 5). The referee is oftentimes assisted by two assistant referees, and sometimes by a fourth official.
Barfoed's test. Barfoed's test is a chemical test used for detecting the presence of monosaccharides. It is based on the reduction of copper(II) acetate to copper(I) oxide (Cu2O), which forms a brick-red precipitate.
Labtestsonline.org explains that the purpose of an Hgb blood test is to determine the amount of hemoglobin that exists in your blood as well as, how well it is supplying your blood cells with oxygen. In patients with bleeding problems such as, heavy menstrual flows, an Hgb test can determine levels of anemia.