OBJECTIVE To compare the effects of different sterilization techniques on ultra-high speed centrifugal tubes and observe the influence on the material physical properties so as to provide bases for optimization of technological process for sterilization of high-precision experimental consumables.

METHODS The ultra-high speed centrifugal tubes made of polypropylene materials were chosen for the research and were sterilized with high-pressure steam (134 ℃), ethylene oxide and hydrogen peroxide at low temperature, respectively. The sterilization effects were verified by biological indicators, and the safety of sterilization process was determined by combining physical monitoring and chemical indicator cards. Vernier caliper was used to measure the size of key parts (nozzle and thread) of the tube body before and after the sterilization, and the deformation rate was evaluated; the compressive strength of the sterilized centrifuge tube was tested under the condition of 100 000 g ultra-high speed centrifugation for 120 min, and the integrity of the tube body surface (cracks, transparency changes, and so on) was visually inspected.

RESULTS The qualified rates of physical, chemical and biological monitoring of the pressure steam sterilization method and the ethylene oxide sterilization method were all 100.00%; the qualified rate of physical monitoring of the hydrogen peroxide low-temperature sterilization method was (99.60 ± 0.20)%, and the qualified rates of chemical and biological monitoring were 100.00%. There was significant difference in the unqualified rate of compressive strength among the three groups of sterilization approaches (F=185.640, P < 0.001), and the unqualified rate of the ethylene oxide sterilization group was lowest (0.78±0.30)%. There was significant difference in the deformation rate of diameter of tube orifice among the three groups (F=32.170, P < 0.001), and the deformation rate of the pressure steam sterilization group was highest (2.31±0.50)%.

CONCLUSIONS The high-pressure steam and hydrogen peroxide are not suitable for the sterilization of ultra-high speed centrifugal tubes made of polypropylene materials, which have direct impact on the material properties. The research proves that the ethylene oxide ensures the sterilization effect and has least impact on the material properties and structural stability, and it should be taken as the preferred approach for sterilization.