In the fractional sterilization process, what sequence correctly describes the steps involved?

In the fractional sterilization process, which is also known as intermittent sterilization, all steps described are essential components to successfully eliminate microorganisms, especially spores.

Firstly, the heating step effectively kills vegetative bacteria present in the material being sterilized. This initial step is crucial as it reduces the microbial load significantly.

Following the initial heating, the material is allowed to incubate. During this incubation period, any bacterial spores that survived the initial heating are encouraged to germinate into their vegetative forms. This is an important phase because spores are highly resistant to heat, and the goal is to convert them into a more susceptible form.

After this incubation phase, a second heating step targets the newly formed vegetative bacteria resulting from the germinated spores. This step again raises the temperature to a level that is sufficient to kill any remaining vegetative bacteria, thus ensuring the sterilization of the material.

Each of these steps is critical in achieving thorough sterilization. Collectively, they illustrate the process's systematic approach to eliminate both vegetative bacteria and spores, demonstrating why acknowledging all these steps as part of the fractional sterilization process is necessary for understanding sterilization techniques in bacteriology.