How is the effectiveness of a GasPak Anaerobic System verified?

The effectiveness is verified by placing an anaerobic indicator strip inside the jar. This strip is impregnated with a dye (such as methylene blue or resazurin) that changes color based on the presence of oxygen. For example, methylene blue becomes colorless under anaerobic conditions and turns blue when exposed to oxygen, while resazurin changes from colorless to pink in the presence of oxygen. Additionally, using the culture of an obligate aerobe (like Pseudomonas) as a biological indicator—where no growth suggests successful anaerobiosis—can also verify the system’s effectiveness.