Final answer:
The proper incubation temperature range for biological indicators in steam sterilization is 55°C ± 2°C for a period of 18–24 hours. This range is critical for the growth and monitoring of bacterial endospores, ensuring that sterilization processes are effectively verified.
Step-by-step explanation:
The correct incubation temperature range for biological indicators used in steam sterilization is 55°C ± 2°C for 18–24 hours. This range is optimal for the growth of naturally heat-resistant bacterial endospores like Geobacillus stearothermophilus, which are commonly used as biological indicators to verify the effectiveness of the sterilization process.
It is important to maintain this temperature range to ensure accurate results, although slight modifications can be made to fit laboratory schedules if directed by an instructor. Note that the specific incubation time and temperature should be recorded if adjustments are made to the standard method.