Convert RLU in cfu/cm2 - microbiological validation
Folosim un aparat pentru teste de sanitatie rapide-Luminometru.
Rezultatul este exprimat in unitati RLU.
Limitele maxime actuale sunt max 30 RLU dupa igienizare si 60 RLU determinari in flux.
Problema este ca nu ne incadram in aceste limite.
Ajutor!
Stie cineva cum se pot converti din RLU in cfu/cm2.
Mai foloseste cineva acest tip de aparat?
Suntem o fabrica de biscuiti.
Folosim un aparat pentru teste de sanitatie rapide-Luminometru.
Rezultatul este exprimat in unitati RLU.
Limitele maxime actuale sunt max 30 RLU dupa igienizare si 60 RLU determinari in flux.
Problema este ca nu ne incadram in aceste limite.
Ajutor!
Stie cineva cum se pot converti din RLU in cfu/cm2.
Mai foloseste cineva acest tip de aparat?
Hi milhaellaaa,
Please communicate in English.
What measurement are you going for, 10-30?
The conversion formula for the RLU-to-predicted CFU is: CFU = 43.45·RLU1.12. This will give you, at best, a rough scatterplot of the expected measurements and it may not be wholly accurate though since there is not a great correlation between the two depending on how clean the environment is.
It may also be your device since each device has different limits and sensitivity. Reach out to the manufacturer to see if there are variations in readings and see if there are any studies or white papers confirming the effectiveness of the device.
Cheers!
Buna mihaellaaa,
On what basis were the current limits set? There is a recommendation from the equipment supplier; It seems to me very low values ...
Are the sanitation tests performed on surfaces or in rinsing water?
During the flow I do not think that the determination is relevant because the product residues interfere with the determination and the value is not exclusively microbiological contamination.
Conversion to cfu / cm2, I don't know if it is regulated somewhere.
In principle, some established maximum limits, if they are not legal provisions, must be validated. It is taken at the same time as the rapid tests, specific tests (eg yeasts and molds, enterobacteriaceae). In order to be relevant, approximately 10 determinations must be made in parallel, possibly from different areas. The results are analyzed and thus the limits are established (eg at values of: 100 RLU, 150 RLU, 170 RLU THE RESULTS OF MICRO DETERMINATIONS ARE IN LIMITS, while for the value of 200 RLU, THE RESULTS OF MICRO DETERMINATIONS ARE OUT OF LIMITS, the max limit should be to be 170 RLU, possibly for a greater precaution we put the limit 150 RLU.
In our company, these validations were performed several years ago. The limits are 150 RLU for CIP washed surfaces (both water and surface determinations) and 500 RLU for manually sanitized surfaces. The values are applicable after sanitization; I explained above that flow determinations are not relevant. The equipment and consumables are 3M brand. We tested other equipment but I did not have repeatability for measurements.