Physically sterilization

This method is used to sterilize equipment / material that resists heat, pressure or radiation. Sterilization can be done by:a. Dry heatDry heat, usually used to sterilize laboratory equipment. For tools such as Petri dishes, bottles or materials such as starch, talc and the like. Generally use the oven. Is the effective temperature of 160oC for 2 hours., Researchers often use temperature of 175oC for 1.5 to 2 hours. For tools such as tweezers needle loop, the tip of the pipette, test tube lip / erlenmeyer / petri dish sterilization typically use methylated spirit lamp or Bunsen.

b. Warm-wetThis can be done by pasteurization, boiling, use of steam, the use of pressurized steam heat wet / humid with the saturated vapor pressure. Very effective for sterilization because it provides a temperature well above the boiling point, the fast, powerful and penetrating power is very high humidity making it easier for the coagulation proteins of microbial cells that cause the cells were destroyed. Effective temperature is 121oC at a pressure of 5 kg/cm2 with the standard time of 15 minutes. Tools used: pressure cooker, autoclave (autoclave)c. RadiationBacteria in particular forms of vegetative cells can be killed by irradiation with ultraviolet (UV) and ionizing rays. Using UV radiation is also used for sterilization of laboratory space, equipment enkas or glass.- UV rays: Bacteria in the air or in the surface layer of a objects exposed to UV rays will die.- Ray Ionization: included are X-ray ionizing rays, alpha rays, beta rays and gamma rays. Sterilization by ionizing rays costly and usually only used in the pharmaceutical industry and medical industry.
              X-ray: The good penetration but large energy needs.
              Alpha rays: It has bactericidal properties but have no penetration power.
              Beta rays: The penetration is slightly larger than the X-ray
              Gamma rays: the radiation power of a large and effective for the sterilization of materials food.