Thank you to everyone who joined our webinar, "Food Safety and Environmental Hygiene Monitoring: The Role of Rapid Hygiene Monitoring Using ATP Bioluminescence." The engaging discussions and thoughtful questions from our audience truly made this event a success!
We’re excited to share answers to some of the most frequently asked questions from the session, covering key topics about rapid hygiene monitoring and the ATP bioluminescence technology.
Click the link to check out our responses! And if you’ve got more questions, please drop them in the comments—we’d love to keep the conversation going!
1. What is the relationship between ATP luciferase cleanliness testing and traditional microbial culture methods? How do RLU and CFU correlate?
The relationship between RLU and CFU is indirect and depends on factors like sample type, surface condition, and contamination level.[1] ATP measures total biological residues, while CFU only measures viable microorganisms. Correlations can be determined through comparative testing, but they often vary across applications.
When testing pure bacterial cultures, it is clear that as the number of bacteria increases, the RLU value also rises, showing a strong correlation. However, on unknown contaminated surfaces, results can differ. For example, a surface with a higher RLU might have fewer cultured bacteria compared to another surface.
This can be explained by the principle of ATP testing: it detects total organic residues, not just bacteria. Many organic substances can contribute ATP to the reaction. This is why ATP testing evaluates overall cleanliness rather than just bacterial contamination.
By using ATP testing to guide cleaning improvements, you can achieve higher cleanliness levels. Imagine an extreme case where a surface is so clean that no organic matter remains—bacteria would have little chance to survive or reproduce.
2. What RLU value is considered acceptable for hygiene monitoring? How can I validate and verify this method when applying it in a hospital setting? Do you have any guidelines or recommendations?
ATP testing has been shown to improve cleanliness standards on healthcare surfaces where feedback from the testing is timely and continuous.[2] Acceptable RLU values depend on the application and surface type. In hospitals, thresholds are typically established based on internal hygiene standards and practical needs.[1] The Spaulding Classification System is often used to define cleaning requirements for equipment, classifying them as critical, semi-critical, or non-critical based on their risk level.
Tianlong has developed a reference range document for ATP testing in hospital settings, which can be used as a guide. We encourage users to validate these recommendations and adapt them to meet the unique requirements of their facilities. Additionally, continuous improvement is key. In cases where caution or failure results are rare, consider lowering your limits to implement a more stringent program. For further validation, ATP-compliant samples can be tested using microbial culture methods to verify consistency between the two approaches.[3]
If you need the guide document, please feel free to contact us.
3. How stable is the ATP test swab?
We recommend storing the swabs in a sealed, light-protected environment. The swabs are stable and maintain their effectiveness for up to 12 months when stored at 2–8°C. Tianlong has conducted stability tests on both Quickswab and Liquswab. If you would like to review the experimental results reports, please feel free to contact us.
[1]Nante N, Ceriale E, Messina G, Lenzi D, Manzi P. Effectiveness of ATP bioluminescence to assess hospital cleaning: a review. J Prev Med Hyg. 2017 Jun;58(2):E177-E183.
[2]Whiteley GS, Glasbey TO, Fahey PP. Using a simplified ATP algorithm to improve data reliability and improve cleanliness standards for surface and medical device hygiene. Infect Dis Health. 2022 Feb;27(1):3-9.
[3]Zhong Xiao, Xiao Lihua, Wu Qingfei. Comparison among 3 methods used to test the cleaning and disinfection effectiveness of high frequent contacted surfaces in hospital[J]. J Trop Med,2018,18(1):32-35.
