FC502 and FC502A membrane filters adopt the principle of membrane filtration method, can be used in concert with various HTY intelligent sterility test pump. The test solution can be filtered through directional motility pressure effect of HTY intelligent sterility test pump. Micro-organisms of test solution can be trapped on the membrane. After filtration, take the repeated used closed membrane filter apart, remove the membrane to culture medium, then detect and count. It is with the characteristics of fully enclosed, advanced sterilization, more safe operation process, etc.