Among the methods for sterilization of collagen solution, microporous membrane filtration and ultraviolet irradiation would not decrease viscosity of the solution, but ultraviolet ray can only irradiating the surface of solution or solution in hyaline tube, which limits sterile efficiency of ultraviolet ray. If every layers of the solution can be irradiated by ultraviolet ray, as the solution in a circulation pipe, by simply rolling the solution, the efficiency of the sterilization would be increased and the quality of the proteins sterilized may be unchanged.OBJECTIVE:
To improve the sterilization method of ultraviolet to be suitable for sterilization of collagen solution.DESIGN, TIME AND SETTING:
The in vitro observational study was conducted at the Institute of Liver Diseases, Fuzhou Hospital for Infectious Diseases from February 2000 to June 2008.MATERIALS:
Sterilization equipment was composed of ultraviolet lamp, reflector (covered on rolling bed), rolling bed and utensil.METHODS:
A utensil was put on the rolling bed. The acidic collagen solution to be sterilized was put in the utensil. The depth of the collagen solution was 8-12 mm. Turn on the ultraviolet lamps and the rolling bed which could roll and mix the solution in the utensil, so the whole collagen solution was irradiated and sterilized. After the irradiation, the collagen solution changed to pH = 7.4 could form a gel.MAIN OUTCOME MEASURES:
The following parameters were measured: depth of the collagen solution; effects of the irradiation time on the efficiency of sterilization efficiency (colony count); Gel formation time after the ultraviolet irradiation (pH = 7.4).RESULTS:
Both the solution of 8-mm depth irradiated for 30 minutes and the solution of 12-mm depth radiated for 90 minutes showed negative bacteria and fungus growth on culture. The collagen solution sterilized by this method could become a gel in 1 hour after changing the pH to 7.4.CONCLUSION:
This simple and effective method of sterilization with ultraviolet and rolling would not prevent the collagen solution from becoming a gel and be suitable for sterilization of the protein solution.