The tubes are applicable to gain high quality serum specimen in biochemical,immunology,serum,etc clinical medicine science inspection.The inner walls areequally coated pro-coagulant which greatly shortened the blood coagulation time. The separation gel is pure substance.It has stable physical and chemical character. Itforms barrier after solidify while apart from the center.Separate the serum and bloodcell completely. Effectively prevent the exchange between the two substances.