Final answer:
The use of spore strip indicators and rapid-readout biological indicators are the most current methods to ensure that proper sterilization conditions have been maintained, as they confirm the destruction of extremely heat-resistant endospores.
Step-by-step explanation:
The most current absolute indication that the proper sterilization time, temperature, and steam have been maintained is through the use of spore strip indicators and rapid-readout biological indicators. Autoclaves alone while critical in the process, do not guarantee sterilization without these biological indicators.
The gold standard for biological indicators uses the endospores of Geobacillus stearothermophilus which can withstand extreme heat to ensure that they have been effectively killed during the sterilization process. Rapid-readout biological indicators can provide results in a shorter time frame making them useful for confirming sterilization soon after a cycle has been completed.